Spectroscopic and molecular modeling studies on the binding of the flavonoid luteolin and human serum albumin.
Luteolin (LUT) is a polyphenolic compound, found in a variety of fruits, vegetables, and seeds, which has a variety of pharmacological properties. In the present contribution, binding of LUT to human serum albumin (HSA), the most abundant carrier protein in the blood, was investigated with the aim of describing the binding mode and parameters of the interaction. The application of circular dichroism, UV-Vis absorption, fluorescence, Raman and surface-enhanced Raman scattering spectroscopy combined with molecular modeling afforded a clear picture of the association mode of LUT to HSA. Specific interactions with protein amino acids were evidenced. LUT was found to be associated in subdomain IIA where an interaction with Trp-214 is established. Hydrophobic and electrostatic interactions are the major acting forces in the binding of LUT to HSA. The HSA conformations were slightly altered by the drug complexation with reduction of alpha-helix and increase of beta-turns structures, suggesting a partial protein unfolding. Also the configuration of at least two disulfide bridges were altered. Furthermore, the study of molecular modeling afforded the binding geometry.
Jurasekova
Zuzana
Z
Instituto de Estructura de la Materia, CSIC, Serrano 121, Madrid 280 06, Spain.
Marconi
Giancarlo
G
Sanchez-Cortes
Santiago
S
Torreggiani
Armida
A
D001665:Binding Sites; D003102:Colloids / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D047311:Luteolin / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D015394:Molecular Structure; D011485:Protein Binding; D017433:Protein Structure, Secondary; D012709:Serum Albumin / Q000737:chemistry / Q000378:metabolism*; D018030:Silver Compounds / Q000737:chemistry; D013057:Spectrum Analysis
D003102:Colloids; D004396:Coloring Agents; D012709:Serum Albumin; D018030:Silver Compounds; D047311:Luteolin