Caltech investigators have identified a broadly neutralizing antibody that may be particularly effective in thwarting HIV. Researchers have been studying these antibodies, which can recognize a protein called the envelope spike, present on the surface of all HIV strains and inhibiting, or neutralizing, the effects of the virus. "In Pamela's lab we use X-ray crystallography and electron microscopy to study protein-protein interactions on a molecular level," says Louise Scharf, a postdoctoral scholar in Bjorkman's laboratory and the first author on the paper. "We previously were able to define the binding site of this antibody on a subunit of the HIV envelope spike, so in this study we solved the three-dimensional structure of this antibody in complex with the entire spike, and showed in detail exactly how the antibody recognizes the virus." Release