INFLUENCE OF BULKY SIDE-CHAINS OF AMINO-ACIDS ON THE SOLUTION CONFORMATION OF PEPTIDE FRAGMENT-(81-92) DERIVATIVES OF CD4, TYICEVEDQKEE, AS STUDIED BY NMR-SPECTROSCOPY AND MOLECULAR MODELING

Solution conformation of CD4 fragment 81-92 TYICEVEDQKEE and two of its benzylated analogues was determined by two-dimensional H-1 NMR spectroscopy, distance geometry and simulated annealing techniques. The structures of both benzylated derivatives are similar but are distinct from that of wild-type dodecapeptide. It is concluded from structural analysis that bulky side chain(s) of amino acid(s) at an appropriate position can have a marked effect on the conformation and thus the functions of a peptide.