The interaction between a human antibody and a protein found on the surface of the HIV-1 virus is revealed in a study in the August 2006 issue of Nature Structural & Molecular Biology.
The antibody, called D5, recognizes an intermediate version of the protein that controls the process by which HIV-1 fuses with host cell membranes.
To gain entry to a host cell, some viruses must first bind to the target cell surface and fuse their membranes with that of the target cell. The protein responsible for controlling the fusion process, called gp41 in HIV-1, must undergo a series of structural changes as membrane fusion occurs. This exposes 'conserved' regions of the molecule, which are ideal targets for antibodies because their sequences mutate less frequently; they tend to 'look' the same to the antibody even in different HIV strain populations.
Andrea Carfi and colleagues report that the human antibody D5 recognizes a gp41 structural intermediate. Understanding how these molecules interact may potentially aid the development of more potent HIV-1 neutralizing antibodies and therapeutic agents. Because other viruses also fuse with host cell membranes, targeting a fusion protein intermediate may be a useful and widely-applicable strategy for drug treatment and vaccination.
Andrea Carfi (IRBM P. Angeletti, Pomezia, Italy)
Abstract available online.
(C) Nature Structural & Molecular Biology press release.
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