화학공학소재연구정보센터
Journal of Physical Chemistry B, Vol.105, No.42, 10416-10423, 2001
Photoinduced electron transfer on beta-sheet cyclic peptides
Gramicidin S analogues that contain a single pyrenyl group and a single p-nitrophenyl group at different positions were synthesized. Photoinduced electron transfer (ET) from an excited pyrenyl group located at the fourth position to a nitrophenyl group located at five different positions was investigated on the beta -sheet chains of the cyclic peptides. The observed ET rate constants displayed a complex dependence on the number of spacer units or on the edge-to-edge distance between the two aromatic groups. The ET rate constants, however, showed a reasonable linear relationship with the equivalent a-distances calculated from the Beratan-Onuchic tunneling pathway model, if through-hydrogen-bond ET was taken into account. The results support the applicability of the tunneling pathway model on both helix and beta -sheet model peptides.