Three-dimensional structure and antigenicity of transmembrane-protein peptides of the human immunodeficiency virus type 1 (original) (raw)

A point mutation (Ala-589 to Thr) in the transmembrane protein of the human immtmodeficlency vnus type 1 (HIV-I ) has been shown to decrease the sensitivity of the virus to the neutralizing effect of human HIV-1 specific antibodIes [( 1990) J Vlrol 64. 3240-32481. Here 17-residue peptides with the parental and mutant sequences were compared. the parental peptide bound antibodies of sera from HIV-l infected persons more frequently and with higher affinity than the mutant peptide. However. according to cu-cular dlchrolsm (CD). NMR spectroscopy and molecular modelling the peptides habe inchstingulshable backbone conformations under a variety of experimental condltlons. These techmquea showed for both peptldes that no ordered hehx was present m water solution. However, for both pepttdes in alcohol-water solutions approximately 60% a-hehx coulu be induced. The three-dimenslonal structures of these pcptides provide a basis for understandmg how this mutation in the transmembrane protein may affect the interactlon with both the outer envelope glycoprotein and with antlbodies.