Keeping stem cells from changing fates

Johns Hopkins researchers have determined why certain stem cells are able to stay stem cells.
The report in the June 4 issue of Cell Stem Cell reveals that an enzyme that changes the way DNA is packaged in cells allows specific genes to be turne…

Artificial enzyme removes natural poison

For the first time ever, a completely man-made chemical enzyme has been successfully used to neutralise a toxin found naturally in fruits and vegetables.
While studying for her PhD in chemistry at the University of Copenhagen Dr. Jeannette Bjerre…

Evolution writ small

A unique experiment at Rice University that forces bacteria into a head-to-head competition for evolutionary dominance has yielded new insights about the way Darwinian selection plays out at the molecular level. An exacting new analysis of the exper…

An enzyme puts the ‘good’ in good cholesterol

An oxidation-fighting enzyme called paraoxonase (PON1) can significantly reduce the risk of heart attacks, according to research reported in today’s rapid access issue of Circulation: Journal of the American Heart Association. The enzyme attaches itself to high-density lipoprotein (HDL), which is known as “good” cholesterol. When PON1 is highly active, the risk for heart attack is cut by 43 percent, says study author Michael Mackness, Ph.D., of the University Department of Medicine, Manchester Royal Infirmary, Manchester, United Kingdom.

Without catalyst, slowest known biological reaction takes 1 trillion years

All biological reactions within human cells depend on enzymes. Their power as catalysts enables biological reactions to occur usually in milliseconds. But how slowly would these reactions proceed spontaneously, in the absence of enzymes – minutes, hours, days? And why even pose the question? One scientist who studies these issues is Dr. Richard Wolfenden, Alumni distinguished professor of biochemistry and biophysics and chemistry at the University of North Carolina at Chapel Hill and a member of the National Academy of Sciences. In 1998, he reported a biological transformation deemed “absolutely essential” in creating the building blocks of DNA and RNA would take 78 million years in water. “Now we’ve found one that’s 10,000 times slower than that,” Wolfenden said.

Sloppy repair helps TB bug resist drugs

Shoddy work by a DNA-repair enzyme allows tuberculosis-causing bacteria to develop antibiotic resistance, scientists at the National Institute of Allergy and Infectious Diseases (NIAID) have discovered. Reported in the current issue of the journal Cell, the finding could lead to new ways to treat TB without risking the development of drug resistance.

New biological sensors for detecting blood glucose

Research conducted by scientists at the Hebrew University of Jerusalem and the U.S. Department of Energy’s Brookhaven National Laboratory has paved the way for development of highly efficient sensors for measuring blood glucose in diabetic patients. Particles the size of a nanometer (that is, one billionth of a meter), which are the building blocks of the science of nanotechnology, have comparable dimensions to animal or plant proteins, thus enabling the integration of these components into hybrid systems exhibiting novel properties.

Gold 'Nanoplugs' Wire Up Enzymes

Researchers have devised a way to use gold nanoparticles as tiny electrical wires to plug enzymes into electrodes. The gold “nanoplugs” help align the molecules for optimal binding and provide a conductive pathway for the flow of electrons. The research, described in the March 21, 2003, issue of Science, may yield more sensitive, inexpensive, noninvasive detectors for measuring biological molecules, including, potentially, agents of bioterrorism.