Vibrational circular dichroism of tetraphenylporphyrin in peptide complexes? A computational study.
Chirality
; 12(4): 191-8, 2000 May.
Article
en En
| MEDLINE
| ID: mdl-10790189
ABSTRACT
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.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Péptidos
/
Porfirinas
/
Dicroismo Circular
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Chirality
Asunto de la revista:
BIOLOGIA MOLECULAR
/
QUIMICA
Año:
2000
Tipo del documento:
Article
País de afiliación:
República Checa