Computational biochemist uncovers a molecular clue to...( TALLAHASSEE Fla. -- A Florida State ...)

TALLAHASSEE, Fla. -- A Florida State University researcher who uses high-powered computers to map the workings of proteins has uncovered a mechanism that gives scientists a better understanding of how evolution occurs at the molecular level.

Such an understanding eventually could lead to the development of new and more effective antiparasitic drugs.

Wei Yang is an assistant professor in FSU's Department of Chemistry and Biochemistry and a faculty member in the university's Institute of molecular biophysics. Working with colleagues from FSU, Duke University and Brandeis University, he recently produced remarkable computer models of an enzyme that carries the unwieldy name of inosine monophosphate dehrydrogenase, or IMPDH for short. IMPDH is responsible for initiating certain metabolic processes in DNA and RNA, enabling the biological system to reproduce quickly.

"In creating these simulations of IMPDH, we observed something that hadn't been seen before," Yang said. "Previously, enzymes were believed to have a single 'pathway' through which they deliver catalytic agents to biological cells in order to bring about metabolic changes. But with IMPDH, we determined that there was a second pathway that also was used to cause these chemical transformations. The second pathway didn't operate as efficiently as the first one, but it was active nevertheless."

Why would an enzyme have two pathways dedicated to the same task? Yang and his colleagues believe that the slower pathway is an evolutionary vestige left over from an ancient enzyme that evolved over eons into modern-day IMPDH.

The finding is significant for several reasons, Yang said.

"First of all, this offers a rare glimpse of evolutionary processes at work on the molecular level," Yang said. "Typically when we talk about evolution, we're referring to a process of adaptation that occurs in a population of organisms over an extended period of time. Our re
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