[Study on the interaction between vincristine and bovine serum albumin].
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 x 10(4) L x mol(-1), 9.5 x 10(3) L x mol(-1), 4.9 x 10(3) L x 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 alpha-helices from 33.5% for free BSA to 29.7%, and with increases of beta-sheet from 13.6% for free BSA to 18.4% in the presence of VCR. The thermodynamic parameters, enthalpy change (deltaH) and entropy change (deltaS), were calculated to be -62.07 kJ x mol(-1) and -129.38 J x (mol x 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.
Chen
Ke-hai
KH
College of Bioengineering, Dalian University, Dalian 116622, China. ckh20055@163.com
Wang
Yu-lian
YL
Guo
Ming
M
Zheng
Xue-fang
XF
Tang
Qian
Q
Ma
Jun-yan
JY
Gao
Da-bin
DB
D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry*; D002942:Circular Dichroism; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics; D014750:Vincristine / Q000737:chemistry*
D000972:Antineoplastic Agents, Phytogenic; D012710:Serum Albumin, Bovine; D014750:Vincristine