We have described a continuous flow ATR-FTIR method for measuring some of the Butyrylcholinesterase enzyme kinetics (Km and Vmax). This is done by developing a circulating system to be close as much as possible to the human circulation using human serum as a source of the enzyme with adjusted pH, isotonicity and temperature to give the maximum affinity of the enzyme towards its substrate (bambuterol). The experiment was running continuously for 90 min to monitor the production of terbutaline from the zero time of its appearance with a measured spectrum in each minute using ZnSe prism. The method was selective and successful for determination of Vmax to be 8.16 × 10-8 mol/min/ml and Km to be 2.28 × 10-5 mol, showing high affinity of the enzyme towards its prodrug substrate Bambuterol. This study critically probes the quantitative ability of the ATR-FTIR method for terbutaline, which was validated according to ICH guidelines showing high accuracy 100.39% and high selectivity towards the produced terbutaline, as the produced spectrums considered as fingerprint of each compound.

中文翻译：

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衰减全反射傅里叶变换红外光谱指纹在线监测班布特罗代谢过程中循环丁酰胆碱酯酶的动力学

我们已经描述了一种用于测量某些丁酰胆碱酯酶动力学（Km 和 Vmax）的连续流 ATR-FTIR 方法。这是通过开发一个循环系统以尽可能接近人体循环来实现的，使用人血清作为酶的来源，调节 pH、等渗性和温度，以提供酶对其底物（班布特罗）的最大亲和力。实验连续运行 90 分钟，以使用 ZnSe 棱镜在每分钟测量光谱，从其出现的零时间监测特布他林的产生。该方法具有选择性并且成功地确定了 Vmax 为 8.16 × 10-8 mol/min/ml 和 Km 为 2.28 × 10-5 mol，表明该酶对其前药底物班布特罗具有高亲和力。