OLIGOMERIZATION OF PROTEGRIN-1 IN THE PRESENCE OF DPC MICELLES - A PROTON HIGH-RESOLUTION NMR-STUDY

Protegrins are members of a family of five Cys-rich naturally occurrin g cationic antimicrobial peptides. The NMR solution structure of prote grin-1 (PG-1) has been previously determined as a monomeric beta-hairp in both in water and in dimethylsulfoxide solution, Protegrins are bac tericidal peptides but their mechanism of action is still unknown. In order to investigate the structural basis of their cytotoxicity, me st udied the effect of Lipid micelles on the structure of PG-1. The NMR s tudy reported in the present work indicates that PG-1 adopts a dimeric structure when it binds to dodecylphosphocholine micelles, Moreover, the amide proton exchange study suggests the possibility of an associa tion between several dimers. (C) 1998 Federation of European Biochemic al Societies.