Tabata M, Kido T, Totani M, Murachi T
Clin Chem. 1985 May;31(5):703-5.
We describe a simple method for determining magnesium in serum by using hexokinase (EC 2.7.1.1) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49). The method is based on determination of the reaction rate of hexokinase activated by Mg2+, which participates in the hexokinase reaction as the substrate in the form of a Mg X ATP2- complex. The reaction rate is determined from the change in absorbance at 340 nm as NADPH is produced by the action of glucose-6-phosphate dehydrogenase. This simple and rapid spectrophotometric method does not require expensive instrumentation, but results correlate satisfactorily with those obtained by atomic absorption spectroscopy. Thus, the present method gives a "true" value for magnesium in serum, a value appreciably lower than that obtained by an earlier colorimetric method, the Xylidyl Blue II method (Biochem Med 7: 208-217, 1973), which lacks specificity.
我们描述了一种通过使用己糖激酶（EC 2.7.1.1）和葡萄糖-6-磷酸脱氢酶（EC 1.1.1.49）来测定血清中镁的简单方法。该方法基于测定由Mg2+激活的己糖激酶的反应速率，Mg2+以MgXATP2-复合物的形式作为底物参与己糖激酶反应。反应速率通过在340nm处吸光度的变化来确定，因为葡萄糖-6-磷酸脱氢酶的作用会产生NADPH。这种简单快速的分光光度法不需要昂贵的仪器设备，但其结果与原子吸收光谱法得到的结果具有良好的相关性。因此，本方法给出了血清中镁的“真实”值，该值明显低于早期缺乏特异性的比色法——二甲苯蓝II法（《生物化学医学》7: 208 - 217, 1973）所得到的值。
