title: Multi-spectroscopic and molecular modelling approach to investigate the interaction of riboflavin with human serum albumin.
abstract: Riboflavin (RF) plays an important role in various metabolic redox reactions in the form of flavin adenine dinucleotide and flavin mononucleotide. Human serum albumin (HSA) is an important protein involved in the transportation of drugs, hormones, fatty acid and other molecules which determine the biodistribution and physiological fate of these molecules. In this study, we have investigated the interaction of riboflavin RF with HSA under simulative physiological conditions using various biophysical, calorimetric and molecular docking techniques. Results demonstrate the formation of riboflavin-HSA complex with binding constant in the order of 104M-1. Fluorescence spectroscopy confirms intermediate strength having a static mode of quenching with stoichiometry of 1:1. Experimental results suggest that the binding site of riboflavin mainly resides in sub-domain IIA of HSA and that ligand interaction increases the α-helical content of HSA. These parameters were further verified by isothermal titration calorimetry ITC which confirms the thermodynamic parameters obtained by fluorescence spectroscopy. Molecular docking was employed to suggest a binding model. Based on thermodynamic, spectroscopic and computational observations it can be concluded that HSA-riboflavin complex is mainly stabilized by various non-covalent forces with binding energy of -7.2 kcal mol-1.
authors.affiliation: a Department of Biochemistry, Faculty of Life Sciences , Aligarh Muslim University , Aligarh , India.
authors.forename: Md Maroof
authors.initials: MM
authors.lastname: Alam
authors.affiliation: b Department of Agricultural Microbiology , Aligarh Muslim University , Aligarh , India.
authors.forename: Faizan
authors.initials: F
authors.lastname: Abul Qais
authors.affiliation: b Department of Agricultural Microbiology , Aligarh Muslim University , Aligarh , India.
authors.forename: Iqbal
authors.initials: I
authors.lastname: Ahmad
authors.affiliation: c Interdisciplinary Biotechnology Unit , Aligarh Muslim University , Aligarh , India.
authors.forename: Parvez
authors.initials: P
authors.lastname: Alam
authors.affiliation: c Interdisciplinary Biotechnology Unit , Aligarh Muslim University , Aligarh , India.
authors.forename: Rizwan
authors.initials: R
authors.lastname: Hasan Khan
authors.affiliation: a Department of Biochemistry, Faculty of Life Sciences , Aligarh Muslim University , Aligarh , India.
authors.forename: Imrana
authors.initials: I
authors.lastname: Naseem
mesh_terms: D001665:Binding Sites; D002942:Circular Dichroism; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D062105:Molecular Docking Simulation; D046912:Multiprotein Complexes / Q000737:chemistry*; D011485:Protein Binding; D012256:Riboflavin / Q000737:chemistry*; D000075462:Serum Albumin, Human / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
chemical_list: D008024:Ligands; D046912:Multiprotein Complexes; D012256:Riboflavin; D000075462:Serum Albumin, Human
keywords: calorimetry; human serum albumin; molecular docking; riboflavin