Higher-protein diets can improve appetite control and satiety

A new study demonstrates that higher-protein meals improve perceived appetite and satiety in overweight and obese men during weight loss.(1) According to the research, published in Obesity, higher-protein intake led to greater satiety throughout the day as well as reductions in both late-night and morning appetite compared to a normal protein diet.

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Researchers use new approach to predict protein function

In a paper published online this month in the journal Nature Chemical Biology, researchers report that they have developed a way to determine the function of some of the hundreds of thousands of proteins for which amino acid sequence data are available, but whose structure and function remain unknown.

Scientists develop a general ‘control switch’ for protein activity

Prof. Mordechai “Moti” Liscovitch and graduate student Oran Erster of the Weizmann Institute’s Biological Regulation Department, have recently developed a unique “switch” that can control the activity of any protein, raising it several-fold or stopping it almost completely. The method provides researchers with a simple and effective tool for exploring the function of unknown proteins, and in the future the new technique may find many additional uses.

The switch has a genetic component and a chemical component: Using genetic engineering, the scientists insert a short segment of amino acids into the amino acid sequence making up the protein. This segment is capable of binding strongly and selectively to a particular chemical drug, which affects the activity level of the engineered protein by increasing or reducing it. When the drug is no longer applied, or when it is removed from the system, the protein returns to its natural activity level.

Ancient retrovirus sheds light on HIV pandemic

Human resistance to a retrovirus that infected chimpanzees and other nonhuman primates 4 million years ago ironically may be at least partially responsible for the susceptibility of humans to HIV infection today.

“This ancient virus is a battle that humans have already won. Humans are not susceptible to it and have probably been resistant throughout millennia,” said senior author Michael Emerman, Ph.D., a member of the Human Biology and Basic Sciences divisions at the Hutchinson Center. “However, we found that during primate evolution, this innate immunity to one virus may have made us more vulnerable to HIV.”

Discovery in plants suggests entirely new approach to treating human cancers

For the first time, scientists from the University of Washington School of Medicine, Indiana University Bloomington and the University of Cambridge have determined how a plant hormone — auxin — interacts with its hormone receptor, called TIR1. Their report, on the cover of this week’s issue of Nature, also may have important implications for the treatment of human disease, because TIR1 is similar to human enzymes that are known to be involved in cancer.

‘Bridge’ protein spurs deadliest stages of breast cancer

A protein known for its ability to “bridge” interactions between other cellular proteins may spur metastasis in breast cancer, the disease’s deadliest stage, a study from Burnham Institute for Medical Research has found.

‘Tribbles’ protein implicated in common and aggressive form of leukemia

Researchers at the University of Pennsylvania School of Medicine have identified a new protein associated with acute myelogenous leukemia (AML). Several lines of evidence point to a protein called Tribbles, named after the furry creatures that took over the starship Enterprise in the original Star Trek series. Tribbles was first described in fruit flies.

“Tribbles had never been directly linked to human malignancy,” says senior author Warren S. Pear, MD, PhD, Associate Professor of Pathology and Laboratory Medicine. “This is a new protein to human cancer and has a specific and overwhelming effect when expressed in hematopoietic stem cells, the cell type that gives rise to all elements of the blood.”

Researchers discover misfolded protein clumps common to dementia, Lou Gehrig’s disease

Scientists have identified a misfolded, or incorrectly formed, protein common to two devastating neurological diseases, frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig’s disease), according to a report in the Oct. 6, 2006, issue of Science. The findings suggest that certain forms of FTD, ALS and possibly other neurological diseases might share a common pathological process.

Grape seed extract halts cell cycle, checking growth of colorectal tumors in mice

Chemicals found in grape seeds significantly inhibited growth of colorectal tumors in both cell cultures and in mice, according to researchers who have already demonstrated the extract’s anti-cancer effects in other tumor types.

Their study, published in the October 18 issue of Clinical Cancer Research, documented a 44 percent reduction of advanced colorectal tumors in the animals, and also revealed, for the first time, the molecular mechanism by which grape seed extract works to inhibit cancer growth. The authors found that it increases availability of a critical protein, Cip1/p21, in tumors that effectively freezes the cell cycle, and often pushes a cancer cell to self destruct.

Researchers make nanosheets that mimic protein formation

How to direct and control the self-assembly of nanoparticles is a fundamental question in nanotechnology.

University of Michigan researchers have discovered a way to make nanocrystals in a fluid assemble into free-floating sheets the same way some protein structures form in living organisms.

Scientists find boosting protein levels staves off heart failure

Boosting levels of a protein in the heart might help protect against the development of heart failure, particularly in those who have had heart attacks.

Cardiology researchers at the Center for Translational Medicine at Jefferson Medical College of Thomas Jefferson University in Philadelphia found that increasing levels of the protein S100A1 above normal helped protect animal hearts from further damage after simulated heart attacks. In some cases, the animals’ heart function hardly changed at all. At the same time, other animals with heart cells lacking the gene for the protein couldn’t handle the stress of a heart blockage; they went on to develop heart failure.

Scientists report full humanization of yeast glycosylation pathway

For the first time, scientists have engineered yeast cells capable of producing a broad repertoire of recombinant therapeutic proteins with fully human sugar structures (glycosylation). These sugar structures ensure a glycoprotein’s biological activity and half-life and to date, have necessitated the expression of therapeutic glycoproteins in mammalian hosts. The accomplishment reported today has the potential to eliminate the need for mammalian cell culture, while improving control over glycosylation, and improving performance characteristics of many therapeutic proteins.

Key fat and cholesterol cell regulator identified, promising target

Researchers at Harvard Medical School and Massachusetts General Hospital have identified how a molecular switch regulates fat and cholesterol production, a step that may help advance treatments for metabolic syndrome, the constellation of diseases that includes high cholesterol, obesity, type II diabetes, and high blood pressure. The study is now published in the online version of the scientific journal Nature and will appear in the August 10th print edition.

Nano Probe May Open New Window Into Cell Behavior

Georgia Tech researchers have created a nanoscale probe, the Scanning Mass Spectrometry (SMS) probe, that can capture both the biochemical makeup and topography of complex biological objects in their normal environment — opening the door for discovery of new biomarkers and improved gene studies, leading to better disease diagnosis and drug design on the cellular level. The research was presented in the July issue of IEE Electronics Letters.

Georgia Tech’s SMS Probe gently pulls biomolecules precisely at a specific point on the cell/tissue surface, ionizes these biomolecules and produces “dry” ions suitable for analysis and then transports those ions to the mass spectrometer.

Researchers Find New Clues To Biochemistry Of ‘Anti-Aging

University of Wisconsin-Madison researchers have found that sirtuins, a family of enzymes linked to a longer life span and healthier aging in humans, may orchestrate the activity of other enzymes involved in metabolic processes in the body.
Published in the Proceedings of the National Academy of Sciences, the study is the first to show that sirtuins directly control specific metabolic enzymes – called AceCSs – in mammalian cells.

The finding, which shines a spotlight on enzymes only recently thought to play a role in the biochemistry of “anti-aging,” has attracted the interest of biotechnology companies seeking to make drugs that delay the aging process and age-related diseases. The drugs could target the metabolic enzymes to produce health benefits.

Scientists Discover a Genetic Code for Organizing DNA

DNA – the long, thin molecule that carries our hereditary material – is compressed around protein scaffolding in the cell nucleus into tiny spheres called nucleosomes. The bead-like nucleosomes are strung along the entire chromosome, which is itself folded and packaged to fit into the nucleus. What determines how, when and where a nucleosome will be positioned along the DNA sequence?

Dr. Eran Segal and research student Yair Field of the Computer Science and Applied Mathematics Department at the Weizmann Institute of Science have succeeded, together with colleagues from Northwestern University in Chicago, in cracking the genetic code that sets the rules for where on the DNA strand the nucleosomes will be situated. Their findings appeared today in Nature.

Scientists reveal possible strategy against obesity, diabetes and infertility

Twelve years ago, scientists discovered leptin–the now-famous hormone that controls appetite, burns calories and performs other crucial physiological activities as well. But the precise mechanism(s) by which leptin carries out these metabolic tasks is still controversial. Now, researchers at the Albert Einstein College of Medicine of Yeshiva University have shown how leptin exerts some of its most important effects.

Their findings, reported in the July 5 issue of Cell Metabolism, suggest a novel approach for duplicating leptin’s actions when the body no longer responds to the hormone.

Neurons grown from embryonic stem cells restore function in paralyzed rats

For the first time, researchers have enticed transplants of embryonic stem cell-derived motor neurons in the spinal cord to connect with muscles and partially restore function in paralyzed animals. The study suggests that similar techniques may be useful for treating such disorders as spinal cord injury, transverse myelitis, amyotrophic lateral sclerosis (ALS), and spinal muscular atrophy. The study was funded in part by the NIH's National Institute of Neurological Disorders and Stroke (NINDS).

Growth factor triggers growth of new blood vessels in the heart

The newest concept for treating coronary artery disease is to induce hearts to grow their own new blood vessels to bypass damaged tissue or clogged arteries. Unfortunately, clinical trials of two important blood-vessel growth factors — fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor (VEGF) — have not produced stellar results.

Now researchers at Washington University School of Medicine in St. Louis have investigated a third signaling molecule — called Sonic hedgehog — that could overcome problems associated with FGF2 and VEGF therapy.

New roles for growth factors: Enticing nerve cells to muscles

During embryonic development, nerve cells hesitantly extend tentacle-like protrusions called axons that sniff their way through a labyrinth of attractive and repulsive chemical cues that guide them to their target.

While several recent studies discovered molecules that repel motor neuron axons from incorrect targets in the limb, scientists at the Salk Institute for Biological Studies have identified a molecule, known as FGF, that actively lures growing axons closer to the right destination. Their findings appear in the June 15 issue of Neuron.

Selenium-protein deficiency raises prostate cancer risk

Selenium, an essential dietary mineral that can act as an antioxidant when incorporated into proteins, has been shown in many studies to reduce the incidence of cancers — notably lung, colorectal and prostate.

Alan Diamond, professor of human nutrition at the University of Illinois at Chicago, and his colleagues report in the May 23 issue of the Proceedings of the National Academy of Sciences on research findings using specially bred transgenic mice that suggest it is the level of selenium-containing proteins in the body that is instrumental in preventing cancer, and that dietary selenium plays a role in stimulating the body's level of these selenoproteins.

Proteome researchers map the entire active protein inventory in cells

Cells are like small cities. They contain all the necessary parts that allow their infrastructure, function, growth, and communication to operate. For over a century scientists have been looking at the structures and organelles in cells using microscopic methods, and then drawing conclusions about their function. Biochemical methods have allowed scientists to examine the inner life of the cell, an organisational unit basic to all life. Now, they are clarifying its structures in detail: from mitochondria, the "factories" of cells, which create energy; to the endoplasmic reticulum, necessary for protein synthesis and metabolic processes; to the Golgi apparatus, responsible for lipid synthesis and producing important energy reserves for cell growth.

Scientists have shown how cutting-edge methods can be used to catalogue the entire inventory of active proteins in cell organelles at a particular moment. Their work sheds considerable light on how cells use proteins. The work is published in the journal Cell.

Worm links cancer risk to ageing

Scientists have discovered that a naturally produced protein that helps protect us from cancer may also determine how long we live.

The findings – published in the highly respected journal Science – open up a new avenue of inquiry into ageing as a risk factor for cancer.

Scientists develop a peptide that delivers drugs into targeted cells like a nanosyringe

Scientists at Yale and the University of Rhode Island report the development of a peptide that can specifically and directly deliver molecules to the inside of cells like a nanosyringe, creating a new tool for drug delivery, gene control and imaging of diseased tissues.

Their "cargo carrier" peptide called pHLIP, for pH (Low) Insertion Peptide, accumulates in the membranes of cells in acidic environments and spontaneously transfers attached molecules across the membrane. The cargo is then released by cleavage of a sulfur-sulfur bond that is only unstable if it is inside the cell.

Groundbreaking research could lead to better drugs

Groundbreaking research published today could revolutionise the way drugs are made and have major implications for the industrial sector, say its authors.

The University of Manchester team, working with colleagues in Bristol, has provided a unique insight into the working of enzymes – biological molecules that speed up chemical reactions in the body.When these chemical reactions go wrong they can lead to disease, so modern drugs are designed to target enzymes and 'switch them off'. But their ability to accelerate chemical reactions means enzymes are also used in a number of commercial processes, including brewing, food processing, domestic cleaning and paper manufacturing.

Hap1 protein links circulating insulin to brain circuits that regulate feeding behavior in mice

Researchers have discovered how the protein Hap1, which is abundant in the brain’s hypothalamus, serves as the link between circulating insulin in the blood and the neural circuitry that controls feeding behavior in mice. Illumination of the neural pathway used by hormones to regulate appetite and eating behavior could eventually provide new drug targets for treating eating disorders and obesity.

Research provides clues to obesity’s cause and hints of new approach for curbing appetite

Hot fudge sundaes and french fries aside, new research suggests obesity is due at least in part to an attraction between leptin, the hormone that signals the brain when to stop eating, and a protein more recently associated with heart disease. Reporting in Nature Medicine, University of Pittsburgh researchers provide evidence that C-reactive protein (CRP) not only binds to leptin but its hold impairs leptin’s role in controlling appetite. The results may help explain why obese people have so much trouble losing weight as well as point to a different target for the pharmaceutical treatment of obesity.

Scientists Reveal Most Detailed Map Of Life-forming Instructions

Researchers at the University of Toronto and the Hospital for Sick Children have recorded the most comprehensive and reliable map of protein interactions in a living organism to date, bringing science one step closer to deciphering and correcting disease-causing genetic instructions in humans and animals.

The findings, which will be released in the March 30 issue of Nature, reveal how researchers used sophisticated proteomic techniques to identify close to 4,000 proteins and 550 protein complexes involved in 7,123 protein-protein interactions in yeast cells, about half of which are novel. Many of the same complexes and protein interactions that go awry in human disease are also found in yeast. While living yeast cells have only 6,000 genes compared to a human’s 25,000, the structures of their encoded proteins and interactions among the proteins are virtually identical to ours.

Researchers have developed a revolutionary new method to detect rare proteins

Researchers at the University of Pennsylvania School of Medicine have developed a paradigm-shifting method for detecting small amounts of proteins in the blood. Applications of this method will make discerning low-abundance molecules associated with cancers (such as breast cancer), Alzheimer’s disease, prion diseases, and possibly psychiatric diseases relatively easy and more accurate compared with the current methodology, including the widely used ELISA (enzyme-linked immunoadsorbent assay).

Study of human protein ‘interaction map’ reveal novel pathways

Discoveries made during the first large-scale analysis of interactions between proteins in our cells hold promise for identifying new genes involved in genetic diseases, according to researchers at Johns Hopkins and the Institute of Bioinformatics (IOB) in Bangalore.

The findings, reported in the March issue of Nature Genetics, were made using a database of more than 25,000 protein-protein interactions compiled by the Hopkins-IOB team. The result is believed to be the most detailed human “interactome” yet describing the interplay of proteins that occur in cells during health and disease.

Scientists find a way to make human collagen

Of all of the materials that make up our bodies, nothing is more ubiquitous than collagen. It is the most important structural protein in the body, reinforcing connective tissue, bones and teeth, and forming long, fibrous cables to strengthen tendons. Collagen forms sheets of tissue that support the skin and every internal organ. There is nothing in the body, in fact, that does not depend in some way on collagen.

In medicine, collagen from animals, principally cows, is used to rebuild tissue destroyed by burns and wounds. Commonly, it is employed in plastic surgery to augment the lips and cheeks of starlets and others seeking perpetual youth. Catgut, the biodegradable sutures made from cow or horse intestines and used in surgery to minimize scarring, is also a form of collagen.
But for such a commonplace and useful protein, collagen has defied the efforts of biomedical researchers who have tried mightily to synthesize it for use in applications ranging from new wound-healing technologies to alleviating arthritis. The reason: Scientists were unable to synthesize the human protein because they had no way to link the easily made short snippets of collagen into the long, fibrous molecules necessary to mimic the real thing.

But now a team of scientists from the University of Wisconsin-Madison, writing this week (Feb. 13, 2006) in the Proceedings of the National Academy of Sciences (PNAS), reports the discovery of a method for making human collagen in the lab.

A New Way of Looking at Molecular Motors

An innovative method of categorizing myosin—one of three molecular “motors” that produce movement within the cells of the body—has dramatically increased the amount of information available about these essential proteins. The studies lay the groundwork for development of treatments for conditions ranging from certain kinds of blindness and kidney disease to neurodegenerative disorders and parasitic diseases such as malaria.

First disease-specific (breast cancer) protein library opens new drug paths

In research that could significantly advance the pace of drug discovery in the fight against breast cancer, Harvard Medical School investigators announce in today’s online Journal of Proteome Research that they have created the first publicly available library of reliably expressible proteins of a human disease, in this case for breast cancer.

Perhaps more significantly, these researchers expressed a subset of the 1,300 protein-expressing complementary DNAs in the library into a model system mimicking cells of a human breast, allowing them to study on a broad scale how these proteins might contribute to the development of breast cancer. Through this comprehensive approach, they identified potentially novel functional activities for both well known and lesser-known breast cancer-associated proteins.

Decoding the cellular machinary

Researchers from Germany announce they have finished the first complete analysis of the “molecular machines” in one of biology’s most important model organisms: S. cerevisiae (baker’s yeast).

The study combined a method of extracting complete protein complexes from cells (tandem affinity purification, developed in 2001 by Bertrand Séraphin at EMBL), mass spectrometry and bioinformatics to investigate the entire protein household of yeast, turning up 257 machines that had never been observed. It also revealed new components of nearly every complex already known.

A component of proteins acts as powerful “nanosprings”

A component of many proteins has been found to constitute one of the most powerful and resilient molecular “springs” in nature, researchers have discovered.

The scientists say their discovery could lead to a new understanding of mechanical processes within the living cell. The discovery also could provide potent nanoscale “shock absorbers” or “gate-opening springs” in tiny nanomachines.