1. College of Bioengineering, Dalian University, Dalian 116622, China 2. Liaoning Key Lab of Bio-organic Chemistry, Dalian University, Dalian 116622, China 3. College of Environment and Chemical Engineering, Dalian 116622, China
Abstract：The interaction between vincristine (VCR) and bovine serum albumin (BSA) was investigated by UV-Vis absorption, fluorescence and circular dichroism (CD) spectra at 296, 303 and 310 K, respectively. With fluorescence quenching method, the binding constants Ka were determined to be 1.5×104 L·mol-1, 9.5×103 L·mol-1, 4.9×103 L·mol-1 and the number of binding site was 1 at three temperatures, respectively. The conformation of BSA was altered (CD data) with the reductions of α-helices from 33.5％ for free BSA to 29.7％, and with increases of β-sheet from 13.6% for free BSA to 18.4% in the presence of VCR. The thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS), were calculated to be －62.07 kJ·mol-1 and －129.38 J·（mol·K）-1 respectively, according to van′t Hoff equation, which indicated that hydrogen bonds and van der walls interactions played major roles in the binding process.
[1] Liu J Q, Tian J N, He W Y, et al. J. Pharmaceutical and Biomedical Anal., 2004, 35: 671. [2] BIAN Wei, WEI Yan-li, WANG Ya-ping, et al（卞 伟，卫艳丽，王亚萍，等）. Spectroscopy and Spectral Analysis（光谱学与光谱分析）, 2006, 26(3): 505. [3] Li Y, He W Y, Tian J N, et al. J. Mol. Struct., 2005, 743: 79. [4] MA Jun-yan, CHEN Ke-hai, ZHENG Xue-fang, et al(马君燕，陈克海，郑学仿，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2007，27(12)：2485. [5] LIU Luo-sheng, WANG Xing-bo, ZHAO Quan-qin, et al(刘洛生，王兴波，赵全芹，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2006，26(6)：1130. [6] Albani J R. Spectrochim. Acta Part A, 1998, 54: 175. [7] Naseen F, Khan R H, Haq S K, et al. Biochim. Biophys. Acta, 2003, 1649: 164. [8] CHEN Guo-zhen, HUANG Xian-zhi, ZHENG Zhu-zi, et al（陈国珍，黄贤智，郑朱梓，等）. Methods of Fluorescence Analysis, 2nd Ed.（荧光分析法, 第2版）. Beijing：Science Press（北京：科学出版社）, 1990. 112. [9] YANG Pin, GAO Fei（杨 频，高 飞）. The Principle of Bioinorganic Chemistry(生物无机化学原理). Beijing: Science Press（北京：科学出版社）, 2002. 331. [10] ZHANG Yong, ZHANG Gui-zhu, WANG Yue-mei（张 勇，张贵珠，王月梅）. Journal of Analytical Science（分析科学学报）, 2000, 16: 447. [11] Ross P D, Subramanian S. Biochemistry, 1981, 20: 3096. [12] Brahms S, Brahms J. Journal of Molecular Biology, 1980, 138(2): 149.
