Rej R
Clin Chem. 1977 Oct;23(10):1903-11.
Human serum incubated with 2-amino-2-methyl-1-propanol (860 mmol/liter) and magnesium ion (270 mumol/liter) at pH 10.35 showed greater alkaline phosphatase (EC 3.1.3.1) activity than if an equal amount of magnesium ion was added at the time of measurement. The apparent increase is due in part to a slight lability of serum alkaline phosphatase in 2-amino-2-methyl-1-propanol, which is prevented by the inclusion of magnesium. For some sera, however, a portion of this increased activity is real rather than artifactual. Use of serum rather than 4-nitrophenylphosphate to initiate the reaction produced relatively low activities and, in some cases, markedly nonlinear (increasing) rate progress curves. The behavior of some commercial lyophilized control sera differed significantly from that of patients' sera, in particular exhibiting a marked lability in the presence of 2-amino-2-methyl-1-propanol. Incubation of these labile materials with Mg2+ slightly improved their stability; addition of Zn2+ plus Mg2+ markedly stimulated and completely protected their alkaline phosphatase activity.
在pH 10.35条件下，将人血清与2-氨基-2-甲基-1-丙醇（860 mmol/升）和镁离子（270 μmol/升）一起孵育，其碱性磷酸酶（EC 3.1.3.1）活性比在测量时加入等量镁离子时更高。这种明显的增加部分归因于血清碱性磷酸酶在2-氨基-2-甲基-1-丙醇中略有不稳定性，而镁的存在可防止这种情况。然而，对于某些血清，这种增加的活性中有一部分是真实的而非人为造成的。使用血清而非4-硝基苯磷酸酯来引发反应产生的活性相对较低，并且在某些情况下，速率进程曲线明显呈非线性（上升）。一些商业冻干对照血清的行为与患者血清有显著差异，特别是在2-氨基-2-甲基-1-丙醇存在下表现出明显的不稳定性。将这些不稳定物质与Mg2+一起孵育可略微提高其稳定性；添加Zn2+加Mg2+可显著刺激并完全保护其碱性磷酸酶活性。
