Raman spectroscopic study of the conformational changes of thyroxine induced by interactions with phospholipid

Comparison of the Raman spectra of thyroxine (L-3,3′,5,5′-tetraiodothyronine) in the pure state and in a 1:5 mixture with phosphatidylcholine reveals spectral differences that reflect structural changes of thyroxine induced by interactions with the phospholipid. These structural changes could be loc...

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Detalles Bibliográficos
Autores: Alvarez, Rosa Maria Susana, Della Védova, Carlos Omar, Mack, Hans George, Farias, Ricardo Norberto, Hildebrandt, Peter
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2002
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/97939
Acceso en línea:http://hdl.handle.net/11336/97939
Access Level:acceso abierto
Palabra clave:CONFORMATIONAL CHANGES
DENSITY FUNCTIONAL THEORY
PHOSPHOLIPID
RAMAN SPECTROSCOPY
THYROXINE
https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
Descripción
Sumario:Comparison of the Raman spectra of thyroxine (L-3,3′,5,5′-tetraiodothyronine) in the pure state and in a 1:5 mixture with phosphatidylcholine reveals spectral differences that reflect structural changes of thyroxine induced by interactions with the phospholipid. These structural changes could be localized in specific parts of the thyroxine molecule on the basis of a vibrational analysis that was carried out by density functional calculations with the B3LYP hybrid functional applying the SDD effective core potential basis set. The calculated (and subsequently scaled) frequencies reveal a good agreement with the experimental data, which together with calculated IR and Raman intensities allow a plausible assignment of most of the IR and Raman bands. Thus, it is found that modes localized in the aromatic β-ring and in the ether group as well as the C-I stretching modes of ring α are affected upon lipid interactions, indicating that thyroxine interacts with the phosphatidylcholine bilayer via penetration of the hydrophobic part of the molecule.