b-hairpin Strands" />

Conversation 11: No. 1

category image Volume: Conversation 11
Issue Number 1
May 2000
ISBN 0-940030-80-2

Solution Structure of an Antibody-Bound HIV-1IIIB V3 Peptide: A Cis Proline Turn Linking Two b-hairpin Strands

The refined solution structure of a peptide representing the full epitope of the HIV-1 IIIB V3 loop in complex with the anti-gp120 antibody Fv fragment was determined using isotope-filtered and isotope-edited NMR. Both the 15N-labeled peptide in complex with the unlabeled Fv and the unlabeled peptide complexed with the uniformly 15N,13C-labeled Fv were investigated. The backbone of the bound peptide adopts a well defined β-hairpin conformation with two twisted anti-parallel β-strands linked by a type VI tight turn comprising residues RGPG. The central glycine and proline residues of the turn are linked by a cis peptide bond. 15N{1H} NOE measurements demonstrated that the backbone of the bound peptide including the central QRGPGR loop is well ordered in the bound state. The V3 loop peptide solution structure is significantly different from the peptide conformation in the X-ray structures of three anti-peptide antibody/V3MN peptide complexes. These differences seem to be dictated by the antibody dependence and HIV strain-specificity of the V3 peptide fold.

Vitali Tugarinov
Jacob Anglister

Department of Structural Biology
The Weizmann Institute of Science
Rehovot 76100, Israel


Subscription is more cost effective than purchasing PDFs on-the-fly.  Click here for details.