Based in part on protein structures determined at the National Synchrotron Light Source (NSLS) at the U.S. Department of Energy's Brookhaven National Laboratory, scientists at the University of Utah have developed new peptides that appear to be significantly more effective at blocking HIV's entry into cells than other drugs in their class. In a paper published online by the Proceedings of the National Academy of Sciences the week of October 8, 2007, the researchers say these peptides are sufficiently potent to begin pre-clinical studies as a new class of agents for the prevention and treatment of HIV/AIDS. Annie Heroux (pictured here), a biologist and crystallography specialist at Brookhaven Lab is co-author of the paper. This structure-assisted design led to the discovery of D-peptides with up to a 40,000-fold improved antiviral potency over previously reported D-peptides. The structures also suggest ways to engineer the peptides to reduce the chance of drug resistance.