苯唑西林钠与胃蛋白酶相互作用的光谱研究

运用荧光光谱、紫外吸收光谱和同步荧光光谱等方法研究在生理酸度pH1.81以及不同温度(288 K,298 K和308 K)条件下胃蛋白酶与苯唑西林钠的相互作用.结果表明,苯唑西林钠对胃蛋白酶有强烈的荧光淬灭作用,且是动态淬灭类型.计算在不同温度下的结合常数K、结合位点数n.由热力学参数ΔG0,说明结合过程是自发进行的.利用同步荧光光谱考察了苯唑西林钠与胃蛋白酶相互作用过程中胃蛋白酶的构象变化.通过F?rster偶极-偶极非辐射能量转移机理确定了苯唑西林钠在胃蛋白酶中与色氨酸残基之间距离R为0.64 nm.

Spectroscopic Study on the Interaction Between Oxacillin Sodium and Pepsin

The interaction between oxacillin sodium and pepsin was investigated by spectrophotometric techniques such as fluorescence and UV-vis absorption at different temperatures （288 K,298 K and 308 K） in physiological buffer solution （pH1.81）.The experimental results indicated that oxacil- lin sodium has a strong ability on quench the intrinsic fluorescence of pepsin through a dynamic quenching procedure.The binding constant K and the number of binding site n for the oxacillin sodi- um - pepsin system were calculated.The negative value of Go reveals that the binding process is a spontaneous process.Synchronous fluorescence spectroscopy was used to investigated the pepsin＇s conformational changes in the process of interaction with oxacillin sodium.The distance between oxacillin sodium and tryptophan residues in pepsin is 0.64 nm by the mechanism of non-radiation energy transfer.