LOCALLY CONSTRAINED TYROSINE ANALOGS WITH RESTRICTED SIDE-CHAIN DYNAMICS

While investigating synthetic locally constrained analogues of amino acids, we have found that a series of tyrosine analogues, such as the 2',6'-dimethyl-beta-methyl-tyrosines, exhibit restricted rotations about their C(beta)-C(gamma) bonds which can be detected in the H-1-NMR spectra of these compounds. The dynamic properties of these tyrosine analogues and their synthetic intermediates are described in this paper. The potential use of these tyrosine analogues in the study of the roles of side chain dynamics played in peptide-receptor interactions and protein functions also is discussed.