title: Biophysical studies of interaction between hydrolysable tannins isolated from Oenothera gigas and Geranium sanguineum with human serum albumin.
abstract: Tannins, secondary plant metabolites, possess diverse biological activities and can interact with biopolymers such as lipids or proteins. Interactions between tannins and proteins depend on the structures of both and can result in changes in protein structure and activity. Because human serum albumin is the most abundant protein in plasma and responsible for interactions with important biological compounds (e.g. bilirubin) and proper blood pressure, therefore, it is very important to investigate reactions between HSA and tannins. This paper describes the interaction between human serum albumin (HSA) and two tannins: bihexahydroxydiphenoyl-trigalloylglucose (BDTG) and 1-O-galloyl-4,6-hexahydroxydiphenoyl-β-d-glucose (OGβDG), isolated from Geranium sanguineum and Oenothera gigas leafs, respectively. Optical (spectrofluorimetric) and chiral optical (circular dichroism) methods were used in this study. Fluorescence analysis demonstrated that OGβDG quenched HSA fluorescence more strongly than BDTG. Both OGβDG and BDTG formed complexes with albumin and caused a red shift of the fluorescence spectra but did not significantly change the protein secondary structure. Our studies clearly demonstrate that the tested tannins interact very strongly with human serum albumin (quenching constant K=88,277.26±407.04 M(-1) and K=55,552.67±583.07 M(-1) respectively for OGβDG and BDTG) in a manner depending on their chemical structure.
authors.affiliation: Department of Biophysics, Faculty of Biology and Chemistry, University of Bialystok, 15-950 Bialystok, Poland. Electronic address: s.sekowski@uwb.edu.pl.
authors.forename: Szymon
authors.initials: S
authors.lastname: Sekowski
authors.affiliation: Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland.
authors.forename: Maksim
authors.initials: M
authors.lastname: Ionov
authors.affiliation: Department of Biophysics, Faculty of Biology and Chemistry, University of Bialystok, 15-950 Bialystok, Poland.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Kaszuba
authors.affiliation: Institute of Bioorganic Chemistry, Academy of Science, Tashkent 143, Uzbekistan.
authors.forename: Saidmukhtar
authors.initials: S
authors.lastname: Mavlyanov
authors.affiliation: Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Bryszewska
authors.affiliation: Department of Biophysics, Faculty of Biology and Chemistry, University of Bialystok, 15-950 Bialystok, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Zamaraeva
mesh_terms: D002942:Circular Dichroism; D031315:Geranium / Q000737:chemistry*; D006801:Humans; D047348:Hydrolyzable Tannins / Q000737:chemistry*; D031664:Oenothera / Q000737:chemistry*; D012709:Serum Albumin / Q000737:chemistry*
chemical_list: D047348:Hydrolyzable Tannins; D012709:Serum Albumin
keywords: Albumin; Circular dichroism; Fluorescence; Tannins