Surface active peptide-mediated porphyrin aggregation

Abstract

Surface active pentapeptide [2(HCOO⁻). Lys-Ala-Ala-Lys(Z)-Tyr-OCH₃] has been synthesized and its micelle formation investigated using conductometric, pH metric, and UV spectroscopic techniques. The double head double tail peptide molecules are shown to interact with water soluble meso-tetrakis (4-sulfonatophenyl)-porphyrin [TPPS]H₂to form characteristic H-type aggregate at low concentrations, as evidenced by UV–Vis and fluorescence spectroscopic techniques. Spectroscopic analysis reveals that the aggregate contains 1:2 porphyrin–peptide combination. The equilibrium constant for the formation of peptide–porphyrin complex has been obtained by using absorption spectral data. The present studies provide new insight into the peptide–porphyrin interaction.