The Study of Induced Circular Dichroism in the Porphyrin-Poly(L-glutamic acid) Complexes

Abstract

The formation conditions for the binary complexes composed of poly(glutamic acid) and cationic porphyrins 5,10,15,20-tetrakis{4-[(trimethylammonio)methyl]phenyl}porphyrin tetrachloride (TATP), 5,10,15,20-tetrakis(1-methyl¬pyridinum-4-yl)porphyrin (TMPyP) and its Cu(II) derivative (CuTMPyP), and the ternary complexes composed of poly(glutamic acid), the same cationic porphyrins TATP, TMPyP and CuTMPyP and anionic porphyrin 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin were studied by electronic circular dichroism spectroscopy. The binary chiral complexes are formed if any of the three cationic porphyrins is used and the polypeptidic matrix possesses the α-helical structure. The ternary chiral complexes are formed if the matrix exhibits α-helical structure and cationic porphyrins TMPyP or CuTMPyP are used. When the metal porphyrin is used, the intensity of circular dichroism bands in spectrum is one order higher.