Photoinduced electron transfer between non-native donor-acceptor moieties incorporated in synthetic polypeptide aggregates.

A series of analogous photoactive polypeptides that form helical homo and hetero aggregates in aqueous media were prepared. A pyrenyl ketone (the principal chromophore and an electron acceptor) was attached to the N-termini. An electron donor, amidoethylcarbazole, was introduced as a side chain of a non-native amino acid, NCb, 14 residues away. Photoinduced electron-transfer rate constants of the order of 10(8) s(-1) between remote pyrene and carbazole were measured. [structure: see text]