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Vibrational circular dichroism of tetraphenylporphyrin in peptide complexes? A computational study
Author(s) -
Bouř Petr,
Záruba Kamil,
Urbanová Marie,
Setnička VladimÍr,
Matějka Pavel,
Fiedler Zdeněk,
Král Vladimír,
Volka Karel
Publication year - 2000
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/(sici)1520-636x(2000)12:4<191::aid-chir5>3.0.co;2-w
Subject(s) - chemistry , raman optical activity , vibrational circular dichroism , tetraphenylporphyrin , porphyrin , circular dichroism , tripeptide , ab initio , spectral line , computational chemistry , ab initio quantum chemistry methods , chirality (physics) , crystallography , peptide , molecule , photochemistry , organic chemistry , astronomy , biochemistry , physics , chiral symmetry breaking , quantum mechanics , nambu–jona lasinio model , quark
The Raman and absorption spectra of tetraphenylporphyrin (TPP) were calculated and compared to experiment. The computation was based on the harmonic molecular force field and electric tensors obtained ab initio at the BPW91/6‐31G* level. Good agreement was found between experimental and calculated frequencies and intensities. In order to estimate whether induced optical activity in chiral complexes interferes with the signal of peptide vibrations, the vibrational circular dichroism (VCD) spectra of TPP were simulated. The magnetic field perturbation theory (MFP) and the gauge‐invariant atomic orbitals (GIAO) were used for the simulation. Such spectra were compared to theoretical VCD intensities of a model tripeptide as well to experimental spectra of a complex of the peptide and tetrakis( p ‐sulfonatophenyl)porphyrin (TSPP). No significant contribution to VCD signal from the TPP residue was found in experimental spectra. Thus, possible peptide conformational changes occurring during the complexation can be monitored directly in the amide I frequency region. Chirality 12:191–198, 2000. © 2000 Wiley‐Liss, Inc.