Scientists at the University of Maryland Baltimore County have mapped a protein that helps give the AIDS virus its structure -- a finding that could usher in drugs capable of rendering the virus harmless by interfering with its life cycle.
Dr. Michael F. Summers, who heads a UMBC laboratory under a grant from the Howard Hughes Medical Institute, said the protein is the essential building block of the capsid -- a shell-like container that houses the virus' genetic material.
The AIDS virus kills by injecting its genetic material into specialized cells of the immune system, turning them into factories for producing viral copies that infect other cells. In the process, the immune system is destroyed.
An effective drug against the AIDS virus, which has infected an estimated 900,000 Americans, might be one that interferes with the capsid's composition or function, Summers said.
"Knowledge of protein structure is an essential element of drug design," Summers, a professor of chemistry, said at a news briefing yesterday.
Publication of his findings today in the journal Science comes as scientists at the International Conference on AIDS in Vancouver, British Columbia, present evidence that a new generation of drugs can eliminate measureable traces of the virus -- possibly keeping the disease at bay -- when combined with older drugs.
The new drugs -- called protease inhibitors -- were developed af-
ter scientists described the molecular structure of protease, an enzyme that plays a key role in viral replication.
Over its six years of existence, Summers' laboratory has drawn attention for its success in characterizing the proteins that give the AIDS virus its form. The virus has three "structural" proteins -- and the UMBC lab has now described all three.
In their latest work, the scientists detailed two-thirds of the capsid protein, a crucial portion known as the "core domain."
Summers, who involves both graduate students and undergraduates in his research, is not only a star on the Catonsville campus but the only Hughes scholar in the state's public university system.
Dr. Jef D. Boeke, a molecular biologist at the Johns Hopkins School of Medicine, said the findings are "of great interest and utility" because the capsid is "the basic skeleton of the virus particle."
"To make a virus infectious, you have to put that skeleton together. If you can interfere with that process -- say with a drug -- you would have a novel way to kill the virus."
About 2,000 identical proteins come together to form the capsid. One way of crippling the virus would be to prevent them from assembling. Another would be to cement them so tightly that they are incapable of releasing their infectious cargo, Summers said.
Summers was joined in his work by post doctoral associate Rossitza K. Gitti, graduate student Brian M. Lee and undergraduate Jill Walker. Scientists from the University of Utah in Salt Lake City provided viral samples, made with the help of genetically engineered bacteria.
Walker attends the college on a Meyerhoff Scholarship, a full four-year scholarship given to talented minorities interested in studying math and science.
Pub Date: 7/12/96