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

Solution conformation of CD4 fragment 81-92 TYICEVEDQKEE and two of it s benzylated analogues was determined by two-dimensional H-1 NMR spect roscopy, distance geometry and simulated annealing techniques. The str uctures of both benzylated derivatives are similar but are distinct fr om that of wild-type dodecapeptide. It is concluded from structural an alysis that bulky side chain(s) of amino acid(s) at an appropriate pos ition can have a marked effect on the conformation and thus the functi ons of a peptide.