Comparison of two thioxopeptide bond photoswitches in insect kinin

摘要

The photoisomerization abilities of secondary thioxopeptide bond(CS-NH) and thioxo prolyl bond(CS-N) incorporated into the C-terminal pentapeptide of insect kinin were compared.H-Phe-Phe-Ψ[CS-NH]-D-Ala-Trp-Gly-NH_2 and H-Phe-Tyr-Ψ[CS-N]- Pro-Trp-Gly-NH_2 were studied by UV-vis absorption.The isomerization energy barriers of the two segments,Ac-Phe-Ψ[CS-NH]- D-Ala-NH_2 and Ac-Tyr-Ψ[CS-N]-Pro-NH_2 picked from the two peptides,were calculated using ab initio method.The cis isomer of CS-N is more stable than...