STABILIZATION OF β-TURN CONFORMATIONS IN PRO-X-SEQUENCES BY DISULPHIDE BRIDGING. SYNTHESIS AND SOLUTION CONFORMATIONS OF FIVE CYCLIC CYSTINE PEPTIDES

Article abstract of DOI:10.1016/S0040-4020(01)83512-2

Five cyclic peptide disulphides of the type <*> have been synthesized, where X= Gly (1), L-Ala (2), D-Ala (3), Aib (4) and L-Leu (5). 1HNMR studies at 270 MHz in CDCl3 and (CD3)2SO provide evidence of a Pro-X β-turn conformation, stabilized by a transannu