Microbiology

In the last 40 years, scientists have perfected ways to determine the knot-like structure of enzymes, but they’ve been stumped trying to translate the structure into an understanding of function – what the enzyme actually does in the body. This puzzle has hindered drug discovery, since many of the most successful drugs work by blocking enzyme action. A team co-led by UCSF’s Brian Shoichet, Steven Almo of the Albert Einstein College of Medicine, and Frank Raushel of Texas A&M describes the first success “decrypting” an enzyme’s function from its structure. If their new strategy works with…

A factor in immune cells regulates human semen and seems to determine whether a man will be fertile, according to a new study. Yousef Al-Abed, PhD, and his colleagues at The Feinstein Institute for Medical Research have isolated an immune substance called macrophage migration inhibitory factor (MIF) in semen samples from infertile and reproductively healthy men. MIF is key to helping sperm mature, which is necessary for its union with an egg. The finding could lead to a diagnostic test to determine fertility status. The study appears in the latest issue of Molecular Medicine. The semen…

In a host of neurological diseases, including multiple sclerosis (MS) and several neuropathies, the protective covering surrounding the nerves – an insulating material called myelin – is damaged. Scientists at the Weizmann Institute of Science have now discovered an important new line of communication between nervous system cells that is crucial to the development of myelinated nerves – a discovery that may aid in restoring the normal function of the affected nerve fibers. Nerve cells (neurons) have long, thin extensions called axons that can reach up to a meter and or more in length. Often…

A synthetic version of a molecule found in the egg cells of the Northern Leopard frog (Rana pipiens) could provide the world with the first drug treatment for brain tumours. Known as Amphinase, the molecule recognises the sugary coating found on a tumour cell and binds to its surface before invading the cell and inactivating the RNA it contains, causing the tumour to die. Although it could potentially be used as a treatment for many forms of cancer, Amphinase offers greatest hope in the treatment of brain tumours, for which complex surgery and chemotherapy are the only current treatments.…

Researchers at the University of Pennsylvania have demonstrated that gene therapy used to restore retinal activity to the blind also restores function to the brain’s visual center, a critical component of seeing. The multi-institutional study led by Geoffrey K. Aguirre, assistant professor of neurology in Penn's School of Medicine, shows that gene therapy can improve retinal, visual-pathway and visual-cortex responses in animals born blind and has the potential to do the same in humans. “The retina of the eye captures light, but the brain is where vision is experienced,” Aguirre said. “The…

Pheromones are a key reason many creatures, including humans, meet. In addition, while mating recognition systems in each species might be unique, pheromones are considered the important common denominator there also. The mating 'language' is a key reason unacceptable mutants that use slightly different signals die off without any offspring. Even among moth species with different types of males and females, two different kinds of pheromones are in action, which was assumed to be the key factor in mate selection. Not so, say researchers from the Institut National de la Recherche Agronomique…

Many of the areas of the human genome previously thought to be deserts are in fact teeming with life. Most known human genes in the genome map are still incompletely annotated, says Professor Alexandre Reymond, from the Centre for Integrative Genomics, University of Lausanne, Switzerland and the Department of Genetic Medicine, University of Geneva, Geneva, Switzerland. “We found that the vast majority of the protein coding genes we studied utilised often in a tissue-specific manner previously unknown set of exons [the regions of DNA within a gene that are transcribed to messenger RNA]…

New research from Colorado State University shows that the function of all genes in mammals is based on circadian – or daily – rhythms. The study refutes the current theory that only 10 percent to 15 percent of all genes were affected by nature’s clock. While scientists have long known that circadian rhythms regulate the behavior of the living, the study shows that daily rhythm dominates all life functions and particularly metabolism. The new study presents oscillation as a basic property of all genes in the organism as opposed to special function of some genes as previously believed. The…

If the Listeria monocytogenes bacteria behind food poisoning are starved of oxygen, they are liable to turn really nasty according to research published today. Limiting oxygen produces bacteria up to 100 times more invasive than similar bacteria grown with ample oxygen supplies. Bjarke Christensen and Tine Licht together with colleagues from Denmark’s National Food Institute set out to investigate whether the growth conditions of Listeria bacteria just prior to being eaten had an effect on their virulence once absorbed by the gut. Guinea pigs were fed food laced with L. monocytogenes, grown…

It may sound counterintuitive to use a microbial protein to improve water quality but some bacteria are doing just that to protect themselves from potentially toxic nanoparticles in their own environments, and clean up crews of the future could potentially do the same thing on a larger scale. A team from Lawrence Livermore National Laboratory, UC Berkeley and Lawrence Berkeley National Laboratory found that bacteria from an abandoned mine excrete proteins that cause metal nanoparticles to aggregate. The bacteria are binding and immobilizing the metals in the nanoparticles and the…