title: Spectroscopic Study on the Interaction between Naphthalimide-Polyamine Conjugates and Bovine Serum Albumin (BSA).
abstract: The effect of a naphthalimide pharmacophore coupled with diverse substituents on the interaction between naphthalimide-polyamine conjugates 1-4 and bovine serum albumin (BSA) was studied by UV absorption, fluorescence and circular dichroism (CD) spectroscopy under physiological conditions (pH = 7.4). The observed spectral quenching of BSA by the compounds indicated that they could bind to BSA. Furthermore, caloric fluorescent tests revealed that the quenching mechanisms of compounds 1-3 were basically static type, but that of compound 4 was closer to a classical type. The Ksv values at room temperature for compound-BSA complexes-1-BSA, 2-BSA, 3-BSA and 4-BSA were 1.438 × 10⁴, 3.190 × 10⁴, 5.700 × 10⁴ and 4.745 × 10⁵, respectively, compared with the value of MINS, 2.863 × 10⁴ at Ex = 280 nm. The obtained quenching constant, binding constant and thermodynamic parameter suggested that the binding between compounds 1-4 with BSA protein, significantly affected by the substituted groups on the naphthalene backbone, was formed by hydrogen bonds, and other principle forces mainly consisting of charged and hydrophobic interactions. Based on results from the analysis of synchronous three-dimensional ﬂuorescence and CD spectra, we can conclude that the interaction between compounds 1-4 and BSA protein has little impact on the BSA conformation. Calculated results obtained from in silico molecular simulation showed that compound 1 did not prefer either enzymatic drug sites I or II over the other. However, DSII in BSA was more beneficial than DSI for the binding between compounds 2-4 and BSA protein. The binding between compounds 1-3 and BSA was hydrophobic in nature, compared with the electrostatic interaction between compound 4 and BSA.
authors.affiliation: Institute of Chemical Biology, Henan University, Kaifeng 475004, China. tzynew@163.com.
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Tian
authors.affiliation: Institute of Chemical Biology, Henan University, Kaifeng 475004, China. 13674974223@163.com.
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Song
authors.affiliation: The Key Laboratory of Natural Medicine and Immuno-Engineering, Henan University, Kaifeng 475004, China. zhaoyuanchem@study.xmu.edu.cn.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Institute of Chemical Biology, Henan University, Kaifeng 475004, China. Zangfenglei@sohu.com.
authors.forename: Feng-Lei
authors.initials: FL
authors.lastname: Zang
authors.affiliation: Institute of Chemical Biology, Henan University, Kaifeng 475004, China. Zhaozhonghua@sohu.com.
authors.forename: Zhong-Hua
authors.initials: ZH
authors.lastname: Zhao
authors.affiliation: School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, China. beyondkaisas@gamail.com.
authors.forename: Nan-Hao
authors.initials: NH
authors.lastname: Chen
authors.affiliation: The Key Laboratory of Natural Medicine and Immuno-Engineering, Henan University, Kaifeng 475004, China. xxjun@zzu.edu.cn.|Huaihe Clinical Institute, Henan University, Kaifeng 475004, China. xxjun@zzu.edu.cn.
authors.forename: Xue-Jun
authors.initials: XJ
authors.lastname: Xu
authors.affiliation: The Key Laboratory of Natural Medicine and Immuno-Engineering, Henan University, Kaifeng 475004, China. wcjsxq@henu.edu.cn.
authors.forename: Chao-Jie
authors.initials: CJ
authors.lastname: Wang
mesh_terms: D000818:Animals; D002417:Cattle; D053644:Naphthalimides / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry*; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D053644:Naphthalimides; D011073:Polyamines; D012710:Serum Albumin, Bovine
keywords: bovine serum albumin (BSA); conjugates; molecular docking; naphthalimide-polyamine; spectroscopic methods