First discovery of animals making their own carotene

Washington, Apr 30 (ANI): In what could be called as the first among animals, insects, known as aphids, can make their own essential nutrients called carotenoids, say University of Arizona researchers.

To date, no other animals are known to make the potent antioxidants.

And scientists had been thinking that the only way animals could obtain the orangey-red compounds was from their diet.

“It is written everywhere that animals do not make carotenoids,” said Nancy Moran, leader of the UA team that overturned the conventional wisdom.

Carotenoids are building blocks for molecules crucial for vision, healthy skin, bone growth and other key physiological functions. Beta-carotene, the pigment that makes carrots orange, is the building block for Vitamin A.

The researchers also figured out how the aphids they studied, known as pea aphids, acquired the ability to make carotenoids.

“What happened is a fungal gene got into an aphid and was copied,” said Moran.

She added that, although gene transfers between microorganisms are common, finding a functional fungus gene as part of an animal”s DNA is a first.

“Animals have a lot of requirements that reflect ancestral gene loss. This is why we require so many amino acids and vitamins in the diet. Until now it has been thought that there is simply no way to regain these lost capabilities. But this case in aphids shows that it is indeed possible to acquire the capacity to make needed compounds,” she said.

“Possibly this will be an extraordinarily rare case. But so far in genomic studies, a single initial case usually turns out to be only an example of something more widespread.”

A lucky accident in the lab plus the recent sequencing of the pea aphid genome made the discovery possible, said Moran.

The researchers have published their discovery in the latest issue of the journal Science. (ANI)

Beer preservative could help reduce ammonia produced by cattle

Washington, April 21 (ANI): Hops, a natural preservative added to beer to check bacterial growth, may hold the key to reducing ammonia produced by cattle, say researchers.

Cattle, deer, sheep, goats and other ruminant animals depend on a slew of naturally occurring bacteria to aid digestion of grass and other fibrous plants in the first of their four stomach chambers, known as the rumen.

According to US Agricultural Research Service (ARS) microbiologist Michael Flythe, the problem comes from one group of bacteria, known as hyper-ammonia-producing bacteria (HABs).

While other bacteria help their bovine hosts convert plant fibres to cud, HABs break down amino acids, a chemical process that produces ammonia and robs the animals of the amino acids they need to build muscle tissue, explains Flythe.

To make up for lost amino acids, cattle growers have to add expensive and inefficient high-protein supplements to their animals” feed.

Flythe, who works at the ARS Forage Animal Production Research Unit (FAPRU) in Lexington, Ky, believes hops can reduce HAB populations.

Flythe put either dried hops flowers or hops extracts in either cultures of pure HAB or a bacterial mix collected from a live cow”s rumen.

Both the hops flowers and the extracts inhibited HAB growth and ammonia production.

Flythe and FAPRU plant physiologist Isabelle Kagan have completed a similar project with more typical forage.

They recently identified a compound in red clover that inhibits HAB.

Results of that study appeared in Current Microbiology.

Flythe also collaborated with FAPRU animal scientist Glen Aiken on a study in which hops had a positive effect on the rumen”s volatile fatty acid ratios, which are important to ruminant nutrition. (ANI)

Well-cooked meat may increase bladder cancer risk

Washington, Apr 20 (ANI): Frequently eating meat, especially the one which is well done or cooked at high temperatures, may increase your chances of developing bladder cancer, according to a new study.

The University of Texas M. D. Anderson Cancer Center study was presented at the American Association for Cancer Research 101st Annual Meeting 2010.

“It”s well known that meat cooked at high temperatures generates heterocyclic amines (HCAs) that can cause cancer,” said study presenter Jie Lin, Ph.D., assistant professor in M. D. Anderson”s Department of Epidemiology. “We wanted to find out if meat consumption increases the risk of developing bladder cancer and how genetic differences may play a part.”

HCAs form when muscle meats, such as beef, pork, poultry or fish, are cooked at high temperatures. They are products of interaction between amino acids, which are the foundation of proteins, and the chemical creatine, which is stored in muscles. Past research has identified 17 HCAs that may contribute to cancer.

This study, which took place over 12 years, included 884 M. D. Anderson patients with bladder cancer and 878 people who did not have cancer. They were matched by age, gender and ethnicity.

Using a standardized questionnaire designed by the National Cancer Institute (NCI), researchers gathered information about each participant”s dietary habits. They then categorized people into four levels, ranging from lowest to highest red meat intake.

The group with the highest red-meat consumption had almost one-and-a-half times the risk of developing bladder cancer as those who ate little red meat.

Specifically, consumption of beef steaks, pork chops and bacon raised bladder cancer risk significantly. Even chicken and fish – when fried – significantly raised the odds of cancer. (ANI)

The secret of truffle”s aroma is in its genes

London, March 30 (ANI): The genome of the delectable Perigord black truffle has been successfully decoded by a team of European researchers.

Scientists say that within its nucleotides reside secrets to the flavour and elusive lifestyle of this fungus, offering clues that could help a truffle industry that is fraught with unpredictable yields and a counterfeit market.

Mycologist Francis Martin, at the French National Institute for Agricultural Research in Nancy, and his colleagues are compiling a database of genetic markers to verify the geographic origins of black truffle populations.

The genome of the black truffle (Tuber melanosporum) includes genes encoding flavour-related sulphur metabolites and enzymes that degrade amino acids.

This shows that its distinctive aroma and flavour is all produced in-house, and not by microbes native to the region in which the truffle grows, as many researchers had thought.

“When we started this work, many thought that truffles could be like cheese or wine, in that the microflora and yeast living on the truffles played a vital role in releasing volatile compounds. But we in fact demonstrated that the volatiles giving rise to the truffle”s perfume are encoded in the truffle”s genome,” Martin said.

Truffle cultivation is notoriously difficult, in part because of its clandestine life cycle as an underground symbiont, in which the fungus trades nutrients with oak-tree roots.

The T. melanosporum genome also reveals that the fungus reproduces sexually more often than researchers thought. Many growers rely on asexual truffle propagation, in which two haploid cells from a single fungus — each with one copy of the genome — fuse to form the diploid fruiting body (the truffle), which has two copies.

Ye, the researchers found two different sets of mating genes in the black truffle, suggesting that two strains of T. melanosporum with opposite mating types combined through sexual reproduction.

Martin advises growers to use both mating types when inoculating oak trees, and to genetically fingerprint the truffles to be sure that they are not from the same family.

The new research has been published online in Nature. (ANI)

Comet”s glancing blow to planet could spark off life

London, March 27 (ANI): A team of scientists has developed a theory which says that striking a glancing blow to a planet could create the perfect conditions in a comet”s icy core to create amino acids – molecules that are vital to forming life on Earth.

According to a report in Nature News, this shock-compression theory for making amino acids has been developed by Nir Goldman and his colleagues at the Lawrence Livermore National Laboratory in Livermore, California.

The researchers wanted to find out what chemical events might occur in an ice grain trapped inside a comet glancing off a planet.

They used around one million computer hours on the powerful Atlas computer cluster at Lawrence Livermore to simulate the possible chemical processes occurring in a single ice grain during such an impact.

In particular, they were looking for amino acids – markers of potential life.

Previous theories for how amino acids on Earth might have come into being include lightning strikes on a primordial soup of simple molecules or the ultraviolet irradiation of interstellar dust grains, but none of the theories proposed so far is definitive.

Goldman”s simulations included 210 molecules: a mixture of water, methanol, ammonia, carbon dioxide and carbon monoxide.

This mix is commonly used by scientists to represent ice in comets.

When a comet strikes a planet, a shock wave travels through it as it comes to a sudden halt.

This, according to Goldman, compresses the comet, and the compression wave travels through the comet faster than the speed of sound.

As a result, the molecules inside deform and bonds break.

Goldman”s group based its models on the impact that a comet travelling at 29 kilometres per second would be likely to experience.

The impact had to be a side-on blow because a head-on impact would probably destroy everything inside.

To unpick the chemistry going on inside the ice, the researchers used density functional theory simulations, a quantum mechanical treatment of the electrons in a molecule.

In the model, if the electrons around the atoms come close enough to those around other atoms a bond will form.

The team noticed that molecules with carbon-nitrogen bonds were forming, including an unstable molecule called carbamide.

This was a hint that amino-acid-forming processes were possible.

In further simulations, the team also saw what looked like the amino acid glycine with carbon dioxide stuck to it.

“This is the first suggestion that a shock impact could drive interesting chemistry within a comet,” said Goldman. (ANI)

Cellular pathway may explain obesity-cancer link

Washington, March 16 (ANI): Previous studies have shown that obesity is linked to cancer. Now, a researcher is on his way to understand the correlation.

University of Alberta researcher Richard Lamb is studying a cell pathway in the human body that regulates cell growth.

In their most recent work, Lamb and his colleagues have found that this pathway can be affected by sources not within the cell, specifically amino acid nutrients. Amino acids are the building blocks of tissues and muscle in the human body.

What makes this interesting is that these amino acids are found to be elevated in obese people.

That means this signalling pathway, called mTOR, could be hyper-activated by these heightened amino acid nutrients and this could affect how human cells respond to stress and disease among a number of other things.

Lamb and his colleagues will now investigate if cancer cells are aided by this potential hyper-activity of the pathway.

The work has been published in the prestigious journal Molecular Cell. (ANI)

How life might evolve with “exotic” biochemistry and solvents

London, September 18 (ANI): Scientists at a new interdisciplinary research group in Austria are working to uncover how life might evolve with “exotic” biochemistry and solvents, such as sulfuric acid instead of water.

The research group for Alternative Solvents as a Basis for Life Supporting Zones in (Exo-) Planetary Systems was established by the University of Vienna.

Traditionally, planets that might sustain life are looked for in the ‘habitable zone’, the region around a star in which Earth-like planets with carbon dioxide, water vapor and nitrogen atmospheres could maintain liquid water on their surfaces.

Consequently, scientists have been looking for biomarkers produced by extraterrestrial life with metabolisms resembling the terrestrial ones, where water is used as a solvent and the building blocks of life, amino acids, are based on carbon and oxygen.

However, these may not be the only conditions under which life could evolve.

“It is time to make a radical change in our present geocentric mindset for life as we know it on Earth,” said scientist Johannes Leitner.

“Even though this is the only kind of life we know, it cannot be ruled out that life forms have evolved somewhere that neither rely on water nor on a carbon and oxygen based metabolism,” he added.

One requirement for a life-supporting solvent is that it remains liquid over a large temperature range.

Water is liquid between 0 degree Celsius and 100 degrees C, but other solvents exist which are liquid over more than 200 degrees C.

Such a solvent would allow an ocean on a planet closer to the central star.

The reverse scenario is also possible. A liquid ocean of ammonia could exist much further from a star.

Furthermore, sulfuric acid can be found within the cloud layers of Venus and it is now known that lakes of methane/ethane cover parts of the surface of the Saturnian satellite Titan.

Consequently, the discussion on potential life and the best strategies for its detection is ongoing and not only limited to exoplanets and habitable zones.

The newly established research group at the University of Vienna, together with international collaborators, will investigate the properties of a range of solvents other than water, including their abundance in space, thermal and biochemical characteristics as well as their ability to support the origin and evolution of life supporting metabolisms. (ANI)

Organic material in ‘dino mummy’ to give clues about its evolution

London, July 2 (ANI): A mummified dinosaur unearthed in North Dakota, US, may contain traces of 66-million-year old organic material, which could provide vital information about its evolution.

The well-preserved fossil of the plant-eating hadrosaur, complete with skin and tendons, was discovered in 1999.

Named “Dakota”, it was a rare find as bacteria in the soil usually break down soft tissue quickly.

However, the rapid burial of Dakota in a waterlogged, low-oxygen environment allowed fossilisation to outpace the normal processes of microbial decay, preserving areas of soft tissue.

According to a report in New Scientist, Phil Manning and Roy Wogelius at the University of Manchester, UK, used electron microscopy and X-ray imaging to study Dakota’s fossilised skin, as well as a claw and a tendon.

They found cell-like structures comparable to those of living vertebrates.

Further analysis of the skin and claw revealed the presence of amino acids – the building blocks of proteins – suggesting that the cell-like structures were indeed cells and that organic material may have been preserved.

Manning said that the presence of amino acids, rather than whole proteins, is a good sign.

After 66 million years, proteins in soft tissue should have broken down into amino acids, so finding large proteins would likely be a sign of contamination.

The high concentrations of amino acids in the fossil, compared with only traces found in the surrounding sediment, support the idea that they came from the fossil.

The researchers hope that further analysis will confirm the presence of organic material and provide fundamental information about the evolution of this species and its descendants. (ANI)

Identification of potential drug target gives new hope for Alzheimer’s patients

London, July 2 (ANI): A collaborative study conducted by researchers from UC Santa Barbara and several other institutions has provided laboratory that a cluster of peptides may be the toxic agent in Alzheimer’s disease.

The researchers believe that the finding made in the laboratory of Michael T. Bowers, a professor of Chemistry and Biochemistry at UCSB, may lead to new drugs for the disease.

In their study report, they have explained the process in which the toxic Amyloid Beta 42 peptides aggregate, and outlined the new technology they use to study these peptides.

“We believe that we have put a face, a structure, on the molecular assembly that is responsible for Alzheimer’s disease,” Nature magazine quoted Bowers as saying.

He and his colleagues used an innovative technology called ion mobility-based mass spectroscopy, a method that allows researchers to investigate the structure, aggregation, and energetics of protein and peptide systems.

The Amyloid Beta (AB) 42 peptide is clipped from a much larger protein, the amyloid precursor protein (APP), and is composed of 42 amino acid residues.

A second peptide, AB40, is 10 times more abundant than AB42 in healthy human brains, and is also clipped from APP. It is identical to AB42 except it is missing the last two amino acids.

Both peptides aggregate, but AB42 more so than AB40.

Bowers points out that AB40 never grows beyond a tetramer-a cluster of four AB40 peptides. As a consequence, it is nontoxic.

By contrast, adds the researcher, AB42 grows to form rings of six units each.

His team say that two of these “six-mer” rings stack to form a dodecamer, or “twelve-mer”, and then the aggregation stops.

These dodecamer clusters are long-lived, but may eventually rearrange to form so-called B-sheet structures, which lead to the large fibrils that form the plaques found in the brains of those with Alzheimer’s disease and other neurodegenerative diseases.

While experimenting on mice, the researchers observed that the animals implanted with the gene that expresses human APP, and hence able to form AB42 in their brains, quickly developed memory deficits-as if they had Alzheimer’s disease.

Since mice have a much faster metabolism than humans, the disease progresses more quickly. Of importance is the fact that the only AB species found in the brains of the transgenic mice correlates with the dodecamer of AB42 characterized in the Bowers lab experiments. These two pieces of data together strongly implicate the dodecamer of AB42 as the toxic agent in Alzheimer’s disease.

“Our group, along with our collaborators, are searching for drug candidates that can prevent AB42 from aggregating to form the toxic dodecamer. While it is early in the search, we are hopeful good candidates can be found. As a consequence, there is a need to find an early marker for Alzheimer’s disease so that we can use these drugs to radically slow down the disease progression,” said Bowers.

Writing about the study in the journal Nature Chemistry, Bowers said that his team’s method was new, but was gaining acceptance in the biological community.

He said that to fully understand the disease, effects of the oligomerization process would have to be observed at the cellular level, however.

“These latest results are a very hopeful thing. I’m more hopeful now than I have ever been that we can make some real progress on this terrible disease,” said Bowers. (ANI)

Duckbilled dino had skin like birds and crocodiles

Washington, July 1 (ANI): A new study of a remarkably preserved fossil of a duckbilled dinosaur has revealed that the prehistoric reptile had skin like that of birds and crocodiles.

According to a report in National Geographic News, advanced imaging and chemical techniques revealed that the 66-million-year-old “mummified” duckbilled dinosaur had two layers of skin, as do modern vertebrates, including humans.

Such a discovery was possible because the dinosaur’s skin fossilized before bacteria had a chance to eat up the tissue.

It is “absolutely amazing to be able to identify organic molecules from soft tissue that belonged to a beast that died over 66 million years ago,” said excavation leader Phillip Manning, a paleontologist at Britain’s University of Manchester. “It’s certainly in my top ten all-time (most significant) fossils,” he added.

Tyler Lyson, a teenager at the time, discovered Dakota, as the fossil was later dubbed, in 1999 on his family’s North Dakota property.

No one knows how the hippo-size animal died. But, scientists do know that the body was probably buried rapidly.

The resulting low-oxygen environment and the apparent lack of disturbance to the site made Dakota a “world-class dinosaur” fossil, according to the new study.

With electron microscopes and x-rays, Manning discovered that Dakota had cell-like structures indicative of two-ply skin: a thin surface layer plus an underlying layer of dense connective tissues.

That’s just like skin of modern birds and reptiles, which scientists believe are closely related to duckbilled dinosaurs.

Protein-recovery techniques used on the skin and a claw detected amino acids, the building blocks of proteins.

Proteins themselves, complex molecules that degrade easily over time, were not found, however.

But, Manning did identify molecules that would have broken down proteins in Dakota’s body.

That’s like finding fragments of a broken vase instead of the intact vase, explained Tom Holtz, a vertebrate paleontologist at the University of Maryland.

“What’s really nice about the new research is this protein-recovery strategy. It’s the first time the skin of such a big plant-eating dinosaur has been analyzed so deeply,” said Holtz.

“That Dakota’s skin resembles modern vertebrate skin is not surprising but nonetheless comforting,” he added.

Understanding the exact environments that froze Dakota in time may help paleontologists better target future fossil hunts, according to lead study author Manning. (ANI)

New technique to detect metabolites from a single drop of blood

Washington, June 19 (ANI): A single drop of blood could soon be able to identify various blood related metabolites-such as sugars, fatty acids, amino acids and other organic substances-from plant or animal tissue samples.

Scientists at the Max Planck Institute for Chemical Ecology in Jena and their colleagues from the Czech Academy of Sciences in Prague have developed a new method to quickly and reliably detect metabolites from only a drop of blood.

Called MAILD, the new technique is based on the classical mass spectrometry (MALDI-TOF/MS), and it enables researchers to measure a large number of metabolites in biological samples.

Thus, the new method may pave the way for targeted and high-throughput metabolomics as well as in medical diagnostics.

Mass spectrometry is an analytical technique used to elucidate the molecular composition and structure of chemical compounds.

Matrix-Assisted Laser Desorption/Ionization (MALDI), wherein bio-molecules (e.g. proteins) are co-crystallized with a chemical substance called a matrix subsequently irradiated with a laser leads to the formation of protein ions, which can be analysed and detected.

But matrices used in the MALDI technique have a substantial disadvantage-the laser beam not only forms ions from the substances of interest, it also forms low-mass ions originating from the matrix.

“The ions that originated from conventional matrices were like a haystack in which we wanted to find a few and important needles,” said Alee Svatoe, head of the mass spectrometry/proteomics research group at the Max Planck Institute.

Thus, instead of improving the search for the “needles”, i.e. metabolites like sugars, fatty acids, amino acids, and other organic acids, the scientists began to alter the matrices with which the samples were applied so that no more interfering matrix-related ions were generated.

In other words, they tried to remove the haystack to make the needles visible.

So the researchers used the Bronsted-Lowry acid-base theory, and formulated conditions for rational selection of matrices that did not generate interfering ions but provided rich mass spectra of particular kinds of metabolites in real samples.

And with the new experimental protocols they called “Matrix-Assisted Ionization/Laser Desorption – MAILD”, the scientists could quickly and reliably determine more than 100 different analytes from single and small-sized samples.

The new MAILD method allows measurements from diverse biological and medical materials.

The technique allowed scientists to determine a wide range of blood-specific organic acids in one drop of human blood, smaller than a micro litre.

If the scientists succeed in not only identifying, but also quantifying the metabolites, MAILD could develop into a fast method for medical and biological diagnostics. (ANI)

Space rock yields important “ingredient in kitchen” on Earth before life began

London, May 27 (ANI): Scientists have found formic acid, a molecule implicated in the origins of life, has been found at record levels on a meteorite that fell into the Tagish Lake in Canada in the year 2000.

According to a report by BBC News, cold temperatures on the lake prevented the volatile chemical from dissipating quickly.

The researchers told a meeting of the American Geophysical Union that the formic acid was extraterrestrial.

Formic acid is one of a group of compounds dubbed “organics”, because they are rich in carbon.

“We are lucky that the meteorite was untouched by humans hands, avoiding contamination by organic compounds that we have on our fingers,” said Dr Christopher Herd, the curator of the University of Alberta’s meteorite collection.

Samples of the meteorite, totalling 850 grams, were collected from Tagish Lake in Canada.

The scientists found levels of formic acid four times higher than had previously been recorded on a meteorite.

“This has for a while been overlooked as we concentrated predominantly on the Murchison meteorite, but now we’ve got another fresh sample and we can start to analyze a different portion of the asteroid belt and therefore a different portion of the Solar System,” said Mark Sephton, a meteorite and geochemistry professor at Imperial College London.

The particular types, or isotopes, of hydrogen that are found in the formic acid show that it most likely formed in the cold regions of space before our Solar System existed.

On Earth, formic acid is commonly found in the stings of insects such as ants, but Professor Sephton said that it is likely to have been an important “ingredient in the kitchen” on Earth before life began.

The acid is known to act as a “reducing agent” – acting as a magnet for oxygen atoms during chemical reactions – and facilitate the conversion of some amino acids into others.

It may also be implicated in the transformation of the more primitive RNA into DNA.

Only one of the four “nucleobases” that make up RNA and DNA is different between the two: uracil is present in RNA while thymine takes its place in DNA.

Professor Sephton’s team found uracil in the Murchison meteorite, but no measurable amount of thymine.

However, formic acid is known to help along the reaction that converts the uracil into thymine.

“The reaction is one of the ways in which you can take some simple molecules and increase the chemical diversity of the pool of pre-biotic molecules,” said Professor Sephton. (ANI)

Scientists to search for aliens by looking at left or right handedness

Washington, April 24 (ANI): If a scientific team working at the National Institute of Standards and Technology (NIST) is right, we may be able to find extraterrestrial life even before it leaves its home planet – by looking for left (or right) handed light.

The technique the team has developed for detecting life elsewhere in the universe will not spot aliens directly.

Rather, it could allow spaceborne instruments to see a telltale sign that life may have influenced a landscape: a preponderance of molecules that have a certain “chirality,” or handedness.

A right-handed molecule has the same composition as its left-handed cousin, but their chemical behavior differs.

Because many substances critical to life favor a particular handedness, Thom Germer and his colleagues think chirality might reveal life’s presence at great distances, and have built a device to detect it.

“You don’t want to limit yourself to looking for specific materials like oxygen that Earth creatures use, because that makes assumptions about what life is,” said Germer, a physicist at NIST.

“But amino acids, sugars, DNA-each of these substances is either right- or left-handed in every living thing,” he added.

Many molecules not associated with life exhibit handedness as well. But, when organisms reproduce, their offspring possess chiral molecules that have the same handedness as those in their parents’ bodies.

As life spreads, the team theorizes, the landscape will eventually have a large amount of molecules that favor one handedness.

“If the surface had just a collection of random chiral molecules, half would go left, half right,” Germer said.

“But life’s self-assembly means they all would go one way. It’s hard to imagine a planet’s surface exhibiting handedness without the presence of self assembly, which is an essential component of life,” he added.

Because chiral molecules reflect light in a way that indicates their handedness, the research team built a device to shine light on plant leaves and bacteria, and then detect the polarized reflections from the organisms’ chlorophyll from a short distance away.

The device detected chirality from both sources.

The team intends to improve its detector so it can look at pond surfaces and then landscape-sized regions on Earth.

According to Germer, if the team continues to get good results, they will propose that it be built into a large telescope or mounted on a space probe.

“We need to be sure we get a signal from our own planet before we an look at others,” he said. (ANI)

Two highly complex organic molecules detected in space

Berlin, April 21 (ANI): Scientists from the Max Planck Institute for Radio Astronomy in Bonn, Germany, Cornell University, USA, and the University of Cologne, Germany, have detected two of the most complex molecules yet discovered in interstellar space: ethyl formate and n-propyl cyanide.

Their computational models of interstellar chemistry also indicate that yet larger organic molecules may be present – including the so-far elusive amino acids, which are essential for life.

The IRAM 30 m telescope in Spain was used to detect emission from molecules in the star-forming region Sagittarius B2, close to the center of our galaxy.

The two new molecules were detected in a hot, dense cloud of gas known as the “Large Molecule Heimat”, which contains a luminous newly-formed star.

The new molecules ethyl formate (C_2 H_5 OCHO) and n-propyl cyanide (C_3 H_7 CN) represent two different classes of molecule – esters and alkyl cyanides – and they are the most complex of their kind yet detected in interstellar space.

Atoms and molecules emit radiation at very specific frequencies, which appear as characteristic “lines” in the electromagnetic spectrum of an astronomical source.

Recognizing the signature of a molecule in that spectrum is rather like identifying a human fingerprint.

“The difficulty in searching for complex molecules is that the best astronomical sources contain so many different molecules that their “fingerprints” overlap, and are difficult to disentangle,” said Arnaud Belloche, scientist at the Max Planck Institute.
“Larger molecules are even more difficult to identify because their “fingerprints” are barely visible: their radiation is distributed over many more lines that are much weaker,” said Holger Muller, researcher at the University of Cologne.

Out of 3700 spectral lines detected with the IRAM telescope, the team identified 36 lines belonging to the two new molecules.

The researchers then used a computational model to understand the chemical processes that allow these and other molecules to form in space.

The computational models suggest that the more complex molecules form section by section, using pre-formed building blocks that are provided by molecules, such as methanol, that are already present on the dust grains.

The computational models show that these sections, or “functional groups”, can add together efficiently, building up a molecular “chain” in a series of short steps.

The two newly-discovered molecules seem to be produced in this way.

“There is no apparent limit to the size of molecules that can be formed by this process – so there’s good reason to expect even more complex organic molecules to be there, if we can detect them,” said Garrod. (ANI)

Milky Way’s centre tastes like raspberries and smells of rum

London, April 21 (ANI): If a long term research by astronomers is anything to go by, then the centre of our of galaxy tastes like raspberries and smells of rum.

According to a report in the Guardian, astronomers searching for the building blocks of life in a giant dust cloud at the heart of the Milky Way have concluded that it contains the chemical ethyl formate, which gives raspberries their flavour and smells of rum.

The unanticipated discovery follows years of work by astronomers who trained their 30m radio telescope on the enormous ball of dust and gas in the hope of spotting complex molecules that are vital for life.

Finding amino acids in interstellar space is a Holy Grail for astrobiologists, as this would raise the possibility of life emerging on other planets after being seeded with the molecules.

In the latest survey, astronomers sifted through thousands of signals from Sagittarius B2, a vast dust cloud at the centre of our galaxy.

While they failed to find evidence for amino acids, they did find a substance called ethyl formate, the chemical responsible for the flavour of raspberries.

“It does happen to give raspberries their flavour, but there are many other molecules that are needed to make space raspberries,” Arnaud Belloche, an astronomer at the Max Planck Institute for Radio Astronomy in Bonn, told the Guardian.

Curiously, ethyl formate has another distinguishing characteristic: it also smells of rum.

The astronomers used the IRAM telescope in Spain to analyse electromagnetic radiation emitted by a hot and dense region of Sagittarius B2 that surrounds a newborn star.

Radiation from the star is absorbed by molecules floating around in the gas cloud, which is then re-emitted at different energies depending on the type of molecule.

While scouring their data, the team also found evidence for the lethal chemical propyl cyanide in the same cloud.

The two molecules are the largest yet discovered in deep space.

Dr Belloche and his colleague Robin Garrod at Cornell University in New York have collected nearly 4,000 distinct signals from the cloud but have only analysed around half of these.

“So far, we have identified around 50 molecules in our survey, and two of those had not been seen before,” said Belloche.

The latest discoveries have boosted the researchers’ morale because the molecules are as large as the simplest amino acid, glycine.

Amino acids are the building blocks of proteins and are widely seen as being critical for complex life to exist anywhere in the universe. (ANI)

First technique to produce effective anti-leukaemia agent developed

Washington, Apr 18 (ANI): More than a decade after discovering kapakahines- marine-derived natural products with anti-leukaemia potential-scientists have found the first technique to synthesise them in laboratory in large quantities, by using only acetylene gas, a handful of amino acids, and a dozen inventive steps.

Kapakahines were isolated from a South Pacific sponge in trace quantities, but its lack of availability stalled any future studies.

But, thanks to the efforts of researchers at Scripps Research Institute that unlimited production of kapakahine is now possible.

Thus, research on the compound can proceed and may eventually lead to new drug treatments.

Cripbrochalina olemda, a common tube-type sponge like organism, produces a compound called kapakahine B, among other molecules of interest, which has shown potential for fighting leukaemia.

The researchers have said that kapakahine B, which has an unusual structure, uses some never-before-seen mechanism to fight cancer cells.

For a long time, researchers around the world have unsuccessfully tried to devise a method for synthesizing the kapakahines.

Scripps researchers, led by Phil Baran, started on with more basic research, in which they successfully synthesized a simpler related compound, psychotrimine, with no known pharmaceutical potential.

Inspired by this, the researchers created a highly reactive and selective chemical component referred to as a quaternary centre that, because of structural similarities, also drives the essential first step in the kapakahines synthesis.

Later, they set out on a somewhat riskier venture to develop a second stage needed to synthesize kapakahines.

Then, the researchers predicted that using the quaternary centre, they could produce two intermediate isomers, or molecules with the same chemical formula but different structures.

One of the isomers was predicted to be an ideal stepping stone toward the kapakahines, but more difficult to make.

They predicted that the second isomer would be much more reactive, and in theory its concentration would grow sufficiently as it moved toward equilibrium with the first isomer.

And finally, they synthesized two kapakahines for the first time and in gram quantities.

One of the compounds, kapakahine B, has shown potential in fighting leukaemia cells, which could further help in developing potential drug treatment.

The research has been published online by the Journal of the American Chemical Society. (ANI)

Origin of sulfur in rocks point to oxygen-rich atmosphere 2.4 billion years ago

Washington, April 17 (ANI): A team of geochemists has come across evidence that Earth’s atmosphere 2.4 billion years ago was oxygen-rich, as pointed out by the origin of sulfur in rocks.

Sedimentary rocks created more than 2.4 billion years ago sometimes have an unusual sulfur isotope composition thought to be caused by the action of ultra violet light on volcanically produced sulfur dioxide in an oxygen poor atmosphere.

Now, a team of geochemists can show an alternative origin for this isotopic composition that may point to an early, oxygen-rich atmosphere.

“The significance of this finding is that an abnormal isotope fractionation (of sulfur) may not be linked to the atmosphere at all,” said Yumiko Watanabe, research associate, Penn State.

“The strongest evidence for an oxygen poor atmosphere 2.4 billion years ago is now brought into question,” she added.

The researchers present the possibility that the rocks with an anomalous sulfur isotope fractionation came from locations on the ocean floor where hydrothermal fluids seeped up from submarine vents through organic carbon rich sediments and mixed with the ocean water.

Other scientists have previously determined that the sulfur dioxide, ultraviolet light reaction in the absence of oxygen can produce the anomalous isotope fractionation.

Watanabe looked at samples of amino acids and sodium sulfur compounds to try to recreate the anomalous sulfur isotope composition in another way.

She chose amino acids as a proxy for organic material because the anomalous sulfur isotopes often come from sedimentary rock, black shale, which also contains abundant mature kerogen – a mixture of organic compounds.

She chose sodium compounds because of the large amounts of sodium and sulfate in the ocean.

Initial experiments used two amino acids – alanine and glycine – and sodium sulfite, which is less oxidized compared to sulfate.

When heated, these did not produce abnormal fractionation.

Watanabe then tested five amino acids, adding histidine, arginine and tryptophan, and mixed them with sodium sulfate.

In this case, alanine and glycine produced the anomalous isotope composition found in the rocks. In all, she ran 32 series of experiments with more than 100 individual samples.

“At high temperatures it sometimes took 24 hours for the sulfate to reduce to sulfide,” said Watanabe. “At lower temperatures it took about two months, 1,000 hours,” she added.

“People never thought that anomalous sulfur isotope fractionation could be caused by a process other than atmospheric reactions,” said Hiroshi Ohmoto, professor of geoscience, Penn State.

“Our study significantly shifts possibilities to something different, to a biological and thermal regime. There are now at least two ways that the anomalous sulfur isotope fractionation seen in some rocks could be achieved,” Ohmoto added. (ANI)

Stem cell therapy helps diabetics become insulin free

Washington, Apr 15 (ANI): In a breakthrough study, a group of patients with type 1 diabetes were freed from daily insulin injections for up to four years following a transplant using their own stem cells.

According to the study in the April 15 issue of JAMA, a theme issue on diabetes, majority of patients with type 1 diabetes who underwent a certain type of stem cell transplantation became insulin free with good glycemic control, and also increased C-peptide levels, an indirect measure of beta-cell function.

Richard K. Burt, M.D., of the Northwestern University Feinberg School of Medicine, Chicago, presented the findings of the study at a JAMA media briefing at the National Press Club in Washington, D.C.

Clinical evidence indicates that there is an inverse association between beta-cell (a type of cell in the pancreas that secretes insulin) preservation and function and chronic complications of type 1 diabetes mellitus (DM), and the higher the C-peptide levels (a byproduct of insulin production, made up of amino acids), the lower the incidence of some types of complications of type 1 DM.

A previous study found that autologous nonmyeloablative hematopoietic stem cell transplantation (HSCT) in 15 patients with newly diagnosed type 1 DM resulted in the majority of patients becoming insulin free during the follow-up, which averaged about 19 months.

“However, it was suggested that subsequent insulin independence was a prolonged honeymoon period due to dietary and exercise changes associated with close posttransplant medical observation,” the authors write, and it was not known if this change was because of an improvement in beta-cell preservation.

HSCT, which uses a patient’s own blood stem cells, involves the removal and treatment of the stem cells, and their return to the patient by intravenous injection.

Dr. Burt and colleagues conducted a study to determine if posttransplant insulin independence was due to improved beta-cell function by monitoring the C-peptide levels of 23 patients who underwent stem cell transplantation. The patients, with type 1 DM, were ages 13-31 years.

Of the 23 patients, 20 experienced time free from insulin (12 continuously and 8 transiently). Patients remained continuously insulin free for an average time of 31 months (range, 14-52 months). One patient had more than 4 years with no exogenous (produced outside the body) insulin use, 4 patients for at least 3 years, 3 patients for at least 2 years, and 4 patients for at least 1 year. Eight patients relapsed and resumed insulin use at low doses. The majority of patients achieved good glycemic control.

In the continuously insulin-free group, average area under the curve (AUC; a type of measurement) of C-peptide levels before transplantation (225.0 ng/mL per 2 hours) showed a significant increase at 24 months after transplantation (785.4 ng/mL per 2 hours) and at 36 months after transplantation (728.1 ng/mL per 2 hours). In the transient insulin-independent group, average AUC of C-peptide levels also increased from 148.9 ng/mL per 2 hours pretransplantation to 546.8 ng/mL per 2 hours at 36 months, which was sustained at 48 months.

In this group, 2 patients regained insulin independence after treatment with the antihyperglycemic drug sitagliptin, which was associated with an increase in C-peptide levels. Two patients developed pneumonia in the hospital, 3 patients developed late endocrine dysfunction, and 9 patients developed oligospermia (sperm deficiency). There were no deaths.

“In conclusion, autologous nonmyeloablative HSCT was able to induce prolonged and significant increases of C-peptide levels associated with absence of or reduction of daily insulin doses in a small group of patients with type 1 DM,” the researchers write. (ANI)

Biochemical changes that put sperm ‘in the mood’ identified

Washington, April 13 (ANI): Making a significant advance towards new infertility treatments and a male contraceptive pill, scientists at Rensselaer Polytechnic Institute have identified key biochemical changes that put sperm “in the mood” for fertilization.

Dr. Mark D. Platt, a researcher from the Department of Chemistry and Chemical Biology, notes that sperm cannot fertilize an egg immediately after entering the female reproductive tract.

He points out that sperm must acquire this ability after undergoing an activation process called “capacitation”.

He further highlights the fact that this process involves phosphorylation-common biological modification that causes cellular activities to be turned “on” by the addition of phosphate molecules to certain amino acids within proteins.

However, the specific biochemical details have been a deep mystery.

Platt and his colleagues used laboratory mice, and compared the extent of phosphorylation in both capacitated and non-capacitated sperm samples.

The researchers identified 44 peptides exhibiting differential phosphorylation, on 59 specific amino acids, suggesting that modification of those particular sites was essential for the capacitation process.

The relative ratio of phosphorylation between the capacitated and non-capacitated samples were also reported, providing the first biochemical description of what puts sperm “in the mood”.

The study appears in ACS’ Journal of Proteome Research, a monthly ublication. (ANI)

Mutations that hide HIV from immune system weaken its ability to replicate

Washington, Apr 13 (ANI): Scientists at University of Oxford have found that mutations that hide HIV from immune system weaken the virus’ ability to replicate.

According to them, when HIV infects a cell, a complex of human immune proteins called HLA (short for human leukocyte antigen) alert killer T cells by displaying bits of the virus on the surface of the cell, in response to which the T-cells trigger immune attack.

They suggest that individuals who have certain types of HLA proteins control infection better than others.

For instance, in people with HLA-B*5703, the virus multiplies less than in people with some other HLA variants likely because killer T cells in these individuals are quick to attack infected cells. However, HIV is tricky.

To get around HLA-B*5703, the virus mutates three amino acids that T cells need to recognize the infected cells, causing the killers to pass by the infected cell unnoticed.

Thus by mutating, the virus becomes invisible to the immune system.

In the new study, lead researcher Hayley Crawford showed that the triple mutant replicated 20 times slower than normal in cell culture.

During the study, the researchers examined Zambian couples in which one HLA-B*5703-expressing person infected with triple-mutant virus passed the infection to a partner who either did or didn’t have the same HLA variant.

When transmitted to a person without HLAB*5703, the virus changed its mutated amino acids back to their original sequence because the benefit of avoiding killer T cells no longer outweighed the cost of reduced replication.

However, when transmitted to another HLA-B*5703-expressing person, the triple-mutated virus came out on top despite its reduced replication. In these individuals, the avoidance of killer T cells allowed the infection to rapidly proceed to clinical illness.

The study has been published in Journal of Experimental Medicine. (ANI)