CAJ | 학술논문

采用荧光光谱法、紫外吸收光谱法和圆二色性光谱(CD)研究了模拟生理条件下左旋紫草素和人血清白蛋白(HSA)的相互作用,计算了反应的结合常数、结合位点数和热力学参数,并探讨了左旋紫草素对人血清白蛋白二级结构的影响.在温度为292、303、310和318 K时,根据Scatchard方程测得左旋紫草素和HSA的结合常数分别为3.118×10~6、0.249×10~6、0.112×10~6 和0.102×10~6 L·mol~(-1),结合位点数分别为1.308、1.094、1.026和1.018;焓变(ΔH)和熵变(ΔS)分别为-104.82 kJ·mol~(-1)、-238.18 J·mol~(-1)·K~(-1),左旋紫草素在人血清白蛋白上的结合位置与色氨酸残基间的距离为2.66 nm.分子模型研究表明,左旋紫草素与HSA在亚结构域ⅡA结合,二者间的作用力主要为疏水和氢键作用力.CD结果表明,左旋紫草素与HSA的键合使HSA中α-螺旋结构含量从55.80%降到52.31%.
채용형광광보법、자외흡수광보법화원이색성광보(CD)연구료모의생리조건하좌선자초소화인혈청백단백(HSA)적상호작용,계산료반응적결합상수、결합위점수화열역학삼수,병탐토료좌선자초소대인혈청백단백이급결구적영향.재온도위292、303、310화318 K시,근거Scatchard방정측득좌선자초소화HSA적결합상수분별위3.118×10~6、0.249×10~6、0.112×10~6 화0.102×10~6 L·mol~(-1),결합위점수분별위1.308、1.094、1.026화1.018;함변(ΔH)화적변(ΔS)분별위-104.82 kJ·mol~(-1)、-238.18 J·mol~(-1)·K~(-1),좌선자초소재인혈청백단백상적결합위치여색안산잔기간적거리위2.66 nm.분자모형연구표명,좌선자초소여HSA재아결구역ⅡA결합,이자간적작용력주요위소수화경건작용력.CD결과표명,좌선자초소여HSA적건합사HSA중α-라선결구함량종55.80%강도52.31%.
The binding reaction between shikonin(SKN) and human serum albumin(HSA) was studied by fluorescence,UV-Vis absorption and circular dichroism(CD) spectra under simulated physiological conditions.The binding equilibrium constant,number of binding site and thermodynamic parameters were calculated,and effect of SKN on secondary structure of HSA was investigated after shikonin bound to HSA.The result indicated that the binding constants at 292,303,310 and 318 K were 3.118×10~6,0.249×10~6,0.112×10~6 and 0.102×10~6 L·mol~(-1),respectively,and the binding sites(n) were 1.308,1.094,1.026 and 1.018,respectively.The enthalpy change(ΔH) and the entropy change(ΔS) were -104.82 kJ·mol~(-1),-238.18 J·mol~(-1)· K~(-1),respectively.The distance between the binding site and shikonin residue was 2.66 nm.The study of molecular simulation indicated that shikonin bound with the subdomain ⅡA of human serum albumins and the interaction between them was dominated by hydrophobic and hydrogen bonds force.In addition,the result of CD spectra indicated that α-helix content of HSA decreased from 55.80% to 52.31% after binding with shikonin.