title: Spectroscopic studies on the interaction of BSA and 5-spiro-3'-piperidine-2″-spiro-3″-indole-4',2″-diones.
abstract: The interaction of 5-spiro-3'-piperidine-2″-spiro-3″-indole-4',2″-diones (SPSDs), an anti-tumor drug, to bovine serum albumin (BSA) in aqueous solution has been investigated by fluorescence spectra and ultraviolet-visible (UV-vis) spectra at pH 7.40. We have studied the effect of four substituents on the SPSD for the first time. The results of fluorescence titration indicated that SPSD can quench the intrinsic fluorescence of BSA and the quenching mechanism has been analyzed. The binding sites number (n), the binding constant (K(A)) and the spatial-distance (r) of SPSD with BSA without or with substituents on the benzene ring at 302 and 310 K have been calculated. The results show that the presence of the substituents increased the binding constant and changed the binding distance between the acceptor and the donor, which possibly results from the formation of SPSD-BSA complex. We have investigated the possible sub-domain on BSA where bind SPSD by displacement experiments. The effect of SPSD on the conformation of BSA has also been analyzed using synchronous fluorescence under experimental conditions.
authors.affiliation: Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, People's Republic of China. yu_xianyong@163.com
authors.forename: Xianyong
authors.initials: X
authors.lastname: Yu
authors.forename: Qing
authors.initials: Q
authors.lastname: Yao
authors.forename: Hongwen
authors.initials: H
authors.lastname: Tao
authors.forename: Ying
authors.initials: Y
authors.lastname: Yang
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Li
authors.forename: Shizhong
authors.initials: S
authors.lastname: Zhu
mesh_terms: D000042:Absorption; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D004735:Energy Transfer; D007700:Kinetics; D008024:Ligands; D008968:Molecular Conformation; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013141:Spiro Compounds / Q000737:chemistry / Q000378:metabolism*; D013696:Temperature
chemical_list: D008024:Ligands; D013141:Spiro Compounds; D012710:Serum Albumin, Bovine