title: [Investigation of interaction between riboflavin and riboflavin binding protein by fluorescence spectroscopy].
abstract: The interaction between riboflavin and egg white riboflavin binding protein (RBP) was investigated using fluorescence spectroscopy. The binding mode, binding constants, thermodynamic parameters between riboflavin and RBP and energy transfer were studied. The experimental results showed that riboflavin has the ability to quench the intrinsic fluorescence of RBP because of a complex formed, and the quenching mechanism is static quenching. The binding constants were 5.35 x 10(8), 1.54 x 10(8), 0.56 x 10(8) L x mol(-1) at 298, 308 and 318 K, respectively. The thermodynamic parameters were calculated, which suggested hydrogen bonds and Van der Waals played a major role in the interaction. The distance and efficiency of energy transfer between riboflavin and RBP were 0.70 nm and 0.39, respectively, based on the theory of Forster nonradiative energy transfer. Furthermore, the synchronous fluorescence spectroscopy was utilized to investigate the conformational transformation.
authors.affiliation: National Research and Development Center for Egg Processing, College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China. wxf334@yahoo.cn
authors.forename: Xiao-fen
authors.initials: XF
authors.lastname: Wu
authors.forename: Zhao-xia
authors.initials: ZX
authors.lastname: Cai
authors.forename: Shu-guo
authors.initials: SG
authors.lastname: Sun
authors.forename: Qun
authors.initials: Q
authors.lastname: Huang
authors.forename: Guo-dong
authors.initials: GD
authors.lastname: Ren
authors.forename: Lan
authors.initials: L
authors.lastname: He
authors.forename: Mei-hu
authors.initials: MH
authors.lastname: Ma
mesh_terms: D004735:Energy Transfer; D005453:Fluorescence; D026901:Membrane Transport Proteins / Q000737:chemistry*; D011485:Protein Binding; D012256:Riboflavin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
chemical_list: D026901:Membrane Transport Proteins; C019079:riboflavin-binding protein; D012256:Riboflavin