Kaplan A E, Weiss E R, Byrne S T, El-Torkey N M, Margolis S A
Science. 1981 May 1;212(4494):553-5. doi: 10.1126/science.7209551.
Lactate dehydrogenase (LDH, E.C. 1.1.1.27) isozymes from three single-cell sources reacted differently with reduced nicotinamide adenine dinucleotide (NADH) purified to published chromatographic and spectrophotometric specifications and free of inhibitors of LDH, when compared with a commercial preparation of NADH. The activity of LDH-1, purified from rabbit erythrocytes, increased the most with inhibitor-free NADH; the next most stimulated were the LDH isozymes from a control hepatocyte line; but hardly responsive at all were the same isozymes from chemically transformed cells. Thus isozyme composition alone did not account for the range of responses to purified NADH. The commercial preparation of NADH used in these studies contains the Strandjörd-Clayson inhibitors, the most potent group identified in NADH preparations relative to LDH activity. The results suggest that specific molecular differences in individual isozymes contribute to the differential response to the Strandjörd-Clayson inhibitors.
与烟酰胺腺嘌呤二核苷酸（NADH）的市售制剂相比，来自三种单细胞来源的乳酸脱氢酶（LDH，E.C. 1.1.1.27）同工酶与纯化至已发表的色谱和分光光度法规格且不含LDH抑制剂的还原型烟酰胺腺嘌呤二核苷酸（NADH）反应不同。从兔红细胞中纯化的LDH-1的活性，在不含抑制剂的NADH作用下增加最多；其次受到最大刺激的是来自对照肝细胞系的LDH同工酶；但化学转化细胞中的相同同工酶几乎没有反应。因此，仅同工酶组成并不能解释对纯化NADH的反应范围。这些研究中使用的NADH市售制剂含有斯特兰德约德-克莱森抑制剂，这是在NADH制剂中相对于LDH活性鉴定出的最有效的一组抑制剂。结果表明，各个同工酶中的特定分子差异导致了对斯特兰德约德-克莱森抑制剂的不同反应。
