Chemists Identify Key Step in Biosynthesis of Carbapenem Antibiotics

: Jocelyn Duffy / 412-268-9982 / jhduffy [a] andrew.cmu (p) edu PITTSBURGH—A team of researchers, including Carnegie Mellon University's Yisong Guo , have revealed a key step in the biosynthesis of carbapenems, a class of antibiotics used to treat some of the most serious drug-resistant bacterial infections. Their 1126/science. Understanding the chemical pathways that underlie the natural production of these molecules could help researchers develop new variants of antibiotics. Carbapenem antibiotics are highly insusceptible to the bacterial enzymes that can cause drug resistance in other types of antibiotics, such as penicillins. The key to carbapenem's ability to avoid resistance is found in its unique chemical structure. Carbapenems contain beta-lactam/pyrrolidine rings that are almost inpenetrable to beta-lactamase enzymes produced by drug-resistant bacteria. This impenetrability comes courtesy of a stereo configuration at the end of the rings that is also key to conferring antibiotic properties on carbapenem molecules.