3c2a

Publication Abstract from PubMed

Although antibodies against the third variable loop (V3) of the HIV-1 viral envelope glycoprotein are among the first neutralizing antibodies to be detected in infected individuals, they are normally restricted in their specificity. X-ray crystallographic studies of V3-specific antibodies have contributed to a more thorough understanding of recognition of this epitope and of conserved features in the V3 loop that could potentially aid in the design of a multi-component vaccine. The human antibody 447-52D exhibits relatively broad neutralization of primary viral isolates compared with other V3-loop antibodies. A crystal structure of Fab 447-52D in complex with a V3 peptide (UG1033) was determined at 2.1 angstroms resolution. The structure was determined using an epitaxially twinned data set and in-house programs to detect and remove overlapping reflections. Although the processed data have lower than desired completeness and slightly higher than normal R values for the resolution, good-quality electron-density maps were obtained that enabled structure determination. The structure revealed an extended CDR H3 loop that forms a beta-sheet with the peptide, with the predominant contacts being main-chain hydrogen bonds. The V3 peptide and Fab show high structural homology with the previously reported structures of other Fab 447-52D complexes, reinforcing the idea that the V3 loop may adopt a small set of conserved structures, particularly around the crown of the beta-hairpin.

Structure determination of an anti-HIV-1 Fab 447-52D-peptide complex from an epitaxially twinned data set.,Dhillon AK, Stanfield RL, Gorny MK, Williams C, Zolla-Pazner S, Wilson IA Acta Crystallogr D Biol Crystallogr. 2008 Jul;D64(Pt 7):792-802. Epub 2008, Jun 18. PMID:18566514^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.