Chen Xiu, Li Yuhua, Zhang Yan, Yang Jianting, Bian Liujiao
College of Life Science, Northwest University, Xi'an 710069, PR China.
College of Life Science, Northwest University, Xi'an 710069, PR China; Weapon Industry 521 Hospital, Xi'an 710065, PR China.
J Chromatogr B Analyt Technol Biomed Life Sci. 2017 Apr 15;1051:75-83. doi: 10.1016/j.jchromb.2017.03.013. Epub 2017 Mar 18.
TEM-1 beta-lactamases can accurately catalyze the hydrolysis of the beta-lactam rings in beta-lactam antibiotics, which make beta-lactam antibiotics lose its activity, and the prerequisite for the hydrolysis procedure in the binding interaction of TEM-1 beta-lactamases with beta-lactam antibiotics is the beta-lactam rings in beta-lactam antibiotics. Therefore, the binding of TEM-1 beta-lactamase to three beta-lactam antibiotics including penicillin G, cefalexin as well as cefoxitin was explored here by frontal affinity chromatography in combination with fluorescence spectra, adsorption and thermodynamic data in the temperature range of 278-288K under simulated physiological conditions. The results showed that all the binding of TEM-1 beta-lactamase to the three antibiotics were spontaneously exothermic processes with the binding constants of 8.718×10, 6.624×10 and 2.244×10 (mol/L), respectively at 288K. All the TEM-1 beta-lactamases were immobilized on the surface of the stationary phase in the mode of monolayer and there existed only one type of binding sites on them. Each TEM-1 beta-lactamase bound with only one beta-lactam antibiotic and hydrogen bond interaction and Van der Waals force were the main forces between them. This work provided an insight into the binding interactions between TEM-1 beta-lactamases and beta-lactam antibiotics, which may be beneficial for the designing and developing of new substrates resistant to TEM-1 beta-lactamases.
TEM-1β-内酰胺酶能够精确催化β-内酰胺类抗生素中β-内酰胺环的水解，使β-内酰胺类抗生素失去活性，而TEM-1β-内酰胺酶与β-内酰胺类抗生素结合相互作用时水解过程的前提是β-内酰胺类抗生素中的β-内酰胺环。因此，本文在模拟生理条件下，通过前沿亲和色谱结合荧光光谱、吸附及278 - 288K温度范围内的热力学数据，研究了TEM-1β-内酰胺酶与包括青霉素G、头孢氨苄以及头孢西丁在内的三种β-内酰胺类抗生素的结合情况。结果表明，在288K时，TEM-1β-内酰胺酶与这三种抗生素的结合均为自发放热过程，结合常数分别为8.718×10、6.624×10和2.244×10（mol/L）。所有TEM-1β-内酰胺酶均以单层模式固定在固定相表面，且其上仅存在一种结合位点。每个TEM-1β-内酰胺酶仅与一种β-内酰胺类抗生素结合，氢键相互作用和范德华力是它们之间的主要作用力。这项工作深入了解了TEM-1β-内酰胺酶与β-内酰胺类抗生素之间的结合相互作用，这可能有助于设计和开发对TEM-1β-内酰胺酶具有抗性的新底物。
