Abstract Under simulated physiological conditions (pH = 7.40), the interaction between cefpiramide sodium and hen egg white lysozyme was studied with multi-spectroscopy and molecular docking. The results showed that cefpiramide sodium quenched the fluorescence of hen egg white lysozyme by static quenching, and the number of binding site n was about 1. The binding distance (r) between cefpiramide sodium and hen egg white lysozyme was obtained based on the Förster nonradioactive resonance energy transfer and r was less than 7 nm, which indicated that there was a non-radiative energy transition in the system. The thermodynamic parameters were obtained from the van't Hoff equation, and the Gibbs free energy ΔG < 0, indicating that the reaction was spontaneous; ΔH < 0, ΔS > 0, indicating hydrophobic interaction played a major role in forming the cefpiramide sodium-hen egg white lysozyme complex. Synchronous spectra, circular dichroism spectra and UV-Vis spectra showed that cefpiramide sodium changed the conformation of hen egg white lysozyme. The molecular docking results showed that the binding position of cefpiramide sodium was close to the active center composed of Asp52 and Glu35 residues, suggesting that cefpiramide sodium could change the microenvironment of amino acid residues at the catalytic active center of hen egg white lysozyme.

中文翻译：

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鸡蛋清溶菌酶与头孢匹胺钠的相互作用：多光谱和计算模拟

摘要 在模拟生理条件下（pH=7.40），采用多光谱和分子对接研究了头孢匹胺钠与鸡蛋清溶菌酶的相互作用。结果表明，头孢匹胺钠通过静态猝灭淬灭鸡蛋清溶菌酶的荧光，结合位点数n约为1。共振能量转移和 r 小于 7 nm，这表明系统中存在非辐射能量转移。热力学参数由范特霍夫方程得到，吉布斯自由能ΔG < 0，表明反应是自发的；ΔH < 0, ΔS > 0, 表明疏水相互作用在形成头孢匹胺钠-鸡蛋清溶菌酶复合物方面起主要作用。同步光谱、圆二色光谱和紫外-可见光谱表明头孢匹胺钠改变了鸡蛋清溶菌酶的构象。分子对接结果表明，头孢匹胺钠的结合位置靠近由Asp52和Glu35残基组成的活性中心，提示头孢匹胺钠可以改变鸡蛋清溶菌酶催化活性中心氨基酸残基的微环境。