title: Comparative study of flavins binding with human serum albumin: a fluorometric, thermodynamic, and molecular dynamics approach.
abstract: Flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) are derivatives of riboflavin (RF), a water-soluble vitamin, more commonly known as vitamin B(2). Flavins have attracted special attention in the last few years because of the recent discovery of a large number of flavoproteins. In this work, these flavins are used as extrinsic fluorescence markers for probing the microheterogeneous environment of a well-known transport protein, human serum albumin (HSA). Steady-state and time-resolved fluorescence experiments confirm that both FMN and FAD bind to the Sudlow's site-1 (SS1) binding pocket of HSA, where Trp214 resides. In the case of RF, a fraction of RF molecules binds at the SS1, whereas the major fraction of RF molecules remains unbound or surface bound to the protein. Moreover, flavin(s)-HSA interactions are monitored with the help of isothermal titration calorimetry, which provides free energy, enthalpy, and entropy changes of binding along with the binding constants. The molecular picture of binding interaction between flavins and HSA is well explored by docking and molecular dynamics studies.
authors.affiliation: Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Pune 411021, Maharashtra, India.
authors.forename: Abhigyan
authors.initials: A
authors.lastname: Sengupta
authors.forename: Wilbee D
authors.initials: WD
authors.lastname: Sasikala
authors.forename: Arnab
authors.initials: A
authors.lastname: Mukherjee
authors.forename: Partha
authors.initials: P
authors.lastname: Hazra
mesh_terms: D001665:Binding Sites; D002942:Circular Dichroism; D005486:Flavin Mononucleotide / Q000737:chemistry / Q000378:metabolism; D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry / Q000378:metabolism; D005415:Flavins / Q000737:chemistry / Q000378:metabolism*; D005470:Fluorometry; D006801:Humans; D056004:Molecular Dynamics Simulation; D011485:Protein Binding; D012709:Serum Albumin / Q000737:chemistry / Q000378:metabolism*; D013816:Thermodynamics
chemical_list: D005415:Flavins; D012709:Serum Albumin; D005182:Flavin-Adenine Dinucleotide; D005486:Flavin Mononucleotide