摘要
利用荧光光谱法研究了杆菌肽与溶菌酶的相互作用。结果表明:杆菌肽能使溶菌酶的内源荧光发生猝灭。在不同温度下研究杆菌肽对溶菌酶的荧光猝灭作用,证明荧光猝灭机理属于二者形成复合物所引起的静态猝灭。利用Stern-Volmer方程处理实验数据,发现杆菌肽与溶菌酶具有1个结合位点,并计算得到了不同温度下杆菌肽与溶菌酶的结合常数(KA):3.60×105(298 K)、1.90×105(308 K)、4.51×104 L/mol(318 K)。通过计算热力学参数,可知杆菌肽与溶菌酶的相互作用是一个吉布斯自由能降低的自发过程,且二者之间的主要作用力类型是静电作用。三维荧光光谱实验显示,杆菌肽的加入引起溶菌酶构象的变化,表现为蛋白质内部色氨酸残基所处微环境的疏水性降低。
The interactions between bacitracin and lysozyme were studied by fluorescence spectroscopy. The results showed that the intrinsic fluorescence of lysozyme could be quenched by bacitracin. The fluorescence quenching of lysozyme was analyzed at different temperatures. The quenching mechanism was accomplished in a static manner by forming a bacitracin-lysozyme complex. The binding parameters were determined according to Stern-Volmer equation, and the thermodynamic parameters were calculated. The results showed that there was only one binding site between bacitracin and lysozyme. The binding constants（KA） between bacitracin and lysozyme at different temperatures were 3.60 ×10^5（298 K）, 1.90 ×10^5（308 K）, and 4.51 ×10^4 L/mol（318 K）, respectively. Thermodynamic analysis indicated that the interaction process was spontaneous, and electrostatic force might be primarily responsible for the interaction. In addition, the effect of bacitracin on the conformation of lysozyme was analyzed by three-dimensional fluorescence spectroscopy. The result indicated that the polarity of the microenvironment around Trp residues decreased.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2016年第9期139-143,共5页
Food Science
基金
保定市科学技术研究与发展指导计划项目(15ZN001)
河北省高等学校科学技术研究项目(QN2015174)
河北大学中西部提升综合实力专项资金资助项目
关键词
杆菌肽
溶菌酶
相互作用
荧光光谱
bacitracin
lysozyme
interaction
fluorescence spectroscopy
