改良的红细胞胆碱酯酶埃尔曼检测法

Improved Ellman procedure for erythrocyte cholinesterase.

作者信息

George P M, Abernethy M H

出版信息

Clin Chem. 1983 Feb;29(2):365-8.

PMID:6821947

Abstract

The procedure of Dietz et al. (Clin. Chem. 19: 1309-1313, 1973) for plasma cholinesterase (EC 3.1.1.7) gives a background absorbance of 1.4 A when extended to erythrocyte cholinesterase (EC 3.1.1.8) measurement, because the peak absorbance of the reaction product, 5-thionitrobenzoate, coincides with the hemoglobin Soret band at 410 nm. Consequently, the precision of erythrocyte cholinesterase measurements is poor, and the test is restricted to laboratories with a spectrophotometer having a high signal-to-noise ratio. Use of the detergent benzethonium chloride (Hyamine 1622) instead of quinidine sulfate to stop enzyme action allows readings to be made at 440 nm because the hemoglobin band is shifted to 405 nm and its peak intensity is decreased. Moreover, detergent micelle interactions shift the peak absorbance of the 5-thionitrobenzoate from 410 to 435 nm. Overall, the blank absorbance is decreased to about 0.4 A. This results in an assay that is twice as precise as the previous version and is suited for use in a routine laboratory with a moderate-quality spectrophotometer. Thus erythrocyte cholinesterase measurements can readily be made, to complement plasma cholinesterase in the investigation of exposure to organophosphates.

摘要

迪茨等人（《临床化学》，1973年，第19卷，第1309 - 1313页）测定血浆胆碱酯酶（EC 3.1.1.7）的方法，在扩展用于测定红细胞胆碱酯酶（EC 3.1.1.8）时，背景吸光度为1.4 A，因为反应产物5 - 硫代硝基苯甲酸的吸光度峰值与血红蛋白在410 nm处的Soret带重合。因此，红细胞胆碱酯酶测量的精密度较差，该检测仅限于配备高信噪比分光光度计的实验室。使用去污剂苄索氯铵（海明1622）代替硫酸奎尼丁来终止酶的作用，可在440 nm处进行读数，因为血红蛋白带移至405 nm，且其峰值强度降低。此外，去污剂胶束相互作用使5 - 硫代硝基苯甲酸的吸光度峰值从410 nm移至435 nm。总体而言，空白吸光度降至约0.4 A。这使得该检测的精密度提高了一倍，适用于配备中等质量分光光度计的常规实验室。因此，可以很容易地进行红细胞胆碱酯酶测量，以补充血浆胆碱酯酶用于有机磷暴露的调查。