CAJ | 학술논문

将互为同分异构体的两种植物药活性组分补骨脂素和异补骨脂素作为研究对象,利用荧光光谱、紫外光谱、圆二色谱及傅立叶变换红外光谱详细比较研究了这两种香豆素类化合物与人血清白蛋白(HSA)的键合作用.不同光谱的结果定性、定量地显示了HSA二级结构变化的程度.依据荧光滴定实验及Van't Hoff公式求出了反应的热力学参数(△H和△S)的值.根据修正后的Stem-Volmer和Scatchard方程和荧光光谱数据分别求得不同温度(296,303,310及318 K)下药物与蛋白相互作用的结合常数及结合位点数;且根据F(o)rster偶极-偶极能量转移理论,求得药物与HSA间的键合距离;利用竞争实验确定了药物在HSA上的键合位点为site Ⅱ.从分子水平上揭示了这两种化合物与HSA相互作用的机制.
장호위동분이구체적량충식물약활성조분보골지소화이보골지소작위연구대상,이용형광광보、자외광보、원이색보급부립협변환홍외광보상세비교연구료저량충향두소류화합물여인혈청백단백(HSA)적건합작용.불동광보적결과정성、정량지현시료HSA이급결구변화적정도.의거형광적정실험급Van't Hoff공식구출료반응적열역학삼수(△H화△S)적치.근거수정후적Stem-Volmer화Scatchard방정화형광광보수거분별구득불동온도(296,303,310급318 K)하약물여단백상호작용적결합상수급결합위점수;차근거F(o)rster우겁-우겁능량전이이론,구득약물여HSA간적건합거리;이용경쟁실험학정료약물재HSA상적건합위점위site Ⅱ.종분자수평상게시료저량충화합물여HSA상호작용적궤제.
Two active components(psoralen and isopsoralen)of Chinese herbs having similar sffuctures were studied.A combination of intrinsic fluorescence spectroscopy,ultraviolet(UV)spectroscopy,circular dichroism(CD),and Fourier transform-infrared(FT-IR)spectroscopy were used to characterize the binding between the two coumarins and human serum albumin(HSA).The results from different spectra indicated qualitative and quantitative changes of the secondary structure of HSA.The thermodynamic functions,enthalpies(△H)and entropies(△S),were calculated from fluorescence titration experiments using Vant'S Hoff equation.The binding constants and number of binding sites for the drug interactions of both drugs with HSA were evaluated using the relevant fluorescence data at different temperatures(296,303,310,and 318 K) and applying modified Stem-Volmer and Scatchard equations.F(o)ster theory of dipole-dipole energy transfer was used to determine the distance between the protein residue and the bound drugs.The competitive experiments suggested that psoralen and isopsoralen bound strongly to HSA and the primary binding site for both drugswas locatedat siteⅡof HSA.