Duncan P H, McKneally S S, MacNeil M L, Fast D M, Bayse D D
Clin Chem. 1984 Jan;30(1):93-7.
In developing a Reference Material for alkaline phosphatase, we studied the stability, kinetic properties, and commutability of separate preparations of the purified enzyme from human liver, intestine, bone, and placenta. The Michaelis constants (Km) for the preparations from liver, bone, and intestine agreed well with the Km values we obtained for five human serum specimens, whereas that for the placental isoenzyme differed significantly. The first three isoenzymes exhibited nearly identical response-surface patterns, which closely paralleled those observed for 12 human serum specimens (commutability), but not that of the placental isoenzyme. Thus, we believe that a reference material could equally well consist of either the bone, intestinal, or liver isoenzyme. All four isoenzymes were satisfactorily stable in temperature-accelerated degradation studies. We chose the liver isoenzyme as an appropriate reference material because liver tissue is easier to obtain than bone or intestine and the isoenzyme is abundant in liver, is easy to extract, and is the one most commonly increased in human serum. This material is stable at -20 degrees C, is free of interfering and degradative enzymes and, being of human origin, is commutable with the enzyme in human serum.
在开发碱性磷酸酶参考物质时，我们研究了从人肝脏、肠道、骨骼和胎盘中分离纯化的酶制剂的稳定性、动力学特性和互换性。肝脏、骨骼和肠道制剂的米氏常数（Km）与我们从五份人血清标本中获得的Km值吻合良好，而胎盘同工酶的Km值则有显著差异。前三种同工酶表现出几乎相同的反应表面模式，这与在12份人血清标本中观察到的模式非常相似（互换性），但胎盘同工酶并非如此。因此，我们认为参考物质可以同样由骨骼、肠道或肝脏同工酶组成。在温度加速降解研究中，所有四种同工酶的稳定性都令人满意。我们选择肝脏同工酶作为合适的参考物质，因为肝脏组织比骨骼或肠道更容易获得，并且该同工酶在肝脏中含量丰富，易于提取，且是人类血清中最常升高的一种。这种物质在-20℃下稳定，不含干扰酶和降解酶，并且由于来源于人类，与人类血清中的酶具有互换性。
