title: Substitution at the C-3 Position of Catechins Has an Influence on the Binding Affinities against Serum Albumin.
abstract: It is known that catechins interact with the tryptophan (Trp) residue at the drug-binding site of serum albumin. In this study, we used catechin derivatives to investigate which position of the catechin structure strongly influences the binding affinity against bovine serum albumin (BSA) and human serum albumin (HSA). A docking simulation showed that (-)-epigallocatechin gallate (EGCg) interacted with both Trp residues of BSA (one at drug-binding site I and the other on the molecular surface), mainly by π-π stacking. Fluorescence analysis showed that EGCg and substituted EGCg caused a red shift of the peak wavelength of Trp similarly to warfarin (a drug-binding site I-specific compound), while 3-O-acyl-catechins caused a blue shift. To evaluate the binding affinities, the quenching constants were determined by the Stern-Volmer equation. A gallate ester at the C-3 position increased the quenching constants of the catechins. Against BSA, acyl substitution increased the quenching constant proportionally to the carbon chain lengths of the acyl group, whereas methyl substitution decreased the quenching constant. Against HSA, neither acyl nor methyl substitution affected the quenching constant. In conclusion, substitution at the C-3 position of catechins has an important influence on the binding affinity against serum albumin.
authors.affiliation: Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, Hyogo 657-8501, Japan. ike.glr.sindai@gmail.com.
authors.forename: Masaki
authors.initials: M
authors.lastname: Ikeda
authors.affiliation: National Agriculture and Food Research Organization, National Food Research Institute, Tsukuba, Ibaraki 305-8642, Japan. mana5998bu@affrc.go.jp.
authors.forename: Manabu
authors.initials: M
authors.lastname: Ueda-Wakagi
authors.affiliation: Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, Hyogo 657-8501, Japan. sssuuntto@gmail.com.
authors.forename: Kaori
authors.initials: K
authors.lastname: Hayashibara
authors.affiliation: Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, Hyogo 657-8501, Japan. kitano_rei@fancl.co.jp.
authors.forename: Rei
authors.initials: R
authors.lastname: Kitano
authors.affiliation: Department of Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura-cho, Nagahama, Shiga 526-0829, Japan. kawase203@yahoo.co.jp.
authors.forename: Masaya
authors.initials: M
authors.lastname: Kawase
authors.affiliation: Department of Organic Fine Chemicals, The Institute of Scientific and Industrial Research, Osaka University, 8-1, Mihogaoka, Ibaraki, Osaka 567-0047, Japan. kunihiro@sanken.osaka-u.ac.jp.
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Kaihatsu
authors.affiliation: Department of Organic Fine Chemicals, The Institute of Scientific and Industrial Research, Osaka University, 8-1, Mihogaoka, Ibaraki, Osaka 567-0047, Japan. kato-n@sanken.osaka-u.ac.jp.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Kato
authors.affiliation: Department of Bioscience and Engineering, College of Systems Engineering and Science, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama 337-8570, Japan. suhara@sic.shibaura-it.ac.jp.
authors.forename: Yoshitomo
authors.initials: Y
authors.lastname: Suhara
authors.affiliation: Department of Bioscience and Engineering, College of Systems Engineering and Science, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama 337-8570, Japan. nao-osa@sic.shibaura-it.ac.jp.
authors.forename: Naomi
authors.initials: N
authors.lastname: Osakabe
authors.affiliation: Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, Hyogo 657-8501, Japan. ashida@kobe-u.ac.jp.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ashida
mesh_terms: D000818:Animals; D002392:Catechin / Q000031:analogs & derivatives / Q000737:chemistry* / Q000378:metabolism; D002417:Cattle; D006801:Humans; D008958:Models, Molecular; D008968:Molecular Conformation; D011485:Protein Binding; D012709:Serum Albumin / Q000737:chemistry* / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000737:chemistry
chemical_list: D012709:Serum Albumin; D012710:Serum Albumin, Bovine; D002392:Catechin; C045651:epigallocatechin gallate
keywords: catechin; docking study; fluorescence analysis; interaction; serum albumin