title: Protein-Flavonoid Interaction Studies by a Taylor Dispersion Surface Plasmon Resonance (SPR) Technique: A Novel Method to Assess Biomolecular Interactions.
abstract: Flavonoids are common polyphenolic compounds widely distributed in fruits and vegetables. These pigments have important pharmacological relevance because emerging research suggests possible anti-cancer and anti-inflammatory properties as well other beneficial health effects. These compounds are relatively hydrophobic molecules, suggesting the role of blood transport proteins in their delivery to tissues. In this study, we assess the binding interactions of four flavonoids (kaempferol, luteolin, quercetin, and resveratrol) with human serum albumin (HSA), the most abundant protein in the blood, and with glutathione S-transferase pi isoform-1 (GSTP1), an enzyme with well-characterized hydrophobic binding sites that plays an important role in detoxification of xenobiotics with reduced glutathione, using a novel Taylor dispersion surface plasmon resonance (SPR) technique. For the first time, HSA sites revealed a high-affinity binding site for flavonoid interactions. Out of the four flavonoids that we examined, quercetin and kaempferol showed the strongest equilibrium binding affinities (K(D)) of 63 ± 0.03 nM and 37 ± 0.07 nM, respectively. GSTP1 displayed lower affinities in the micromolar range towards all of the flavonoids tested. The interactions of flavonoids with HSA and GSTP1 were studied successfully using this novel SPR assay method. The new method is compatible with both kinetic and equilibrium analyses.
authors.affiliation: Moran Eye Center, University of Utah School of Medicine, 65 Mario Capecchi Drive, Salt Lake City, UT 84132, USA. preejith.vachali@hsc.utah.edu.
authors.forename: Preejith P
authors.initials: PP
authors.lastname: Vachali
authors.affiliation: Moran Eye Center, University of Utah School of Medicine, 65 Mario Capecchi Drive, Salt Lake City, UT 84132, USA. binxing.li@hsc.utah.edu.
authors.forename: Binxing
authors.initials: B
authors.lastname: Li
authors.affiliation: Moran Eye Center, University of Utah School of Medicine, 65 Mario Capecchi Drive, Salt Lake City, UT 84132, USA. brian.besch@hsc.utah.edu.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Besch
authors.affiliation: Moran Eye Center, University of Utah School of Medicine, 65 Mario Capecchi Drive, Salt Lake City, UT 84132, USA. paul.bernstein@hsc.utah.edu.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Bernstein
mesh_terms: D001665:Binding Sites; D005419:Flavonoids / Q000737:chemistry / Q000378:metabolism*; D051549:Glutathione S-Transferase pi / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D044949:Kaempferols / Q000378:metabolism; D007700:Kinetics; D047311:Luteolin / Q000378:metabolism; D011485:Protein Binding; D011794:Quercetin / Q000378:metabolism; D000077185:Resveratrol; D012709:Serum Albumin / Q000737:chemistry* / Q000378:metabolism*; D013267:Stilbenes / Q000378:metabolism; D020349:Surface Plasmon Resonance
chemical_list: D005419:Flavonoids; D044949:Kaempferols; D012709:Serum Albumin; D013267:Stilbenes; C006552:kaempferol; D011794:Quercetin; C496556:GSTP1 protein, human; D051549:Glutathione S-Transferase pi; D047311:Luteolin; D000077185:Resveratrol
keywords: age-related macular degeneration; flavonoids; glutathione s-transferase pi isoform-1; human serum albumin; nutraceutical; taylor dispersion