Comte J, Gautheron D C
Biochimie. 1978;60(11-12):1298-1305.
Malate dehydrogenase, reputed to be a soluble matricial enzyme, is shown to be also strongly associated with the inner membrane, in pig heart mitochondria. Repeated sonications, water washes, freezing-thawing cycles are not very effective to remove malate dehydrogenase activity from inner membranes, which whatever the treatment, remains important. This activity is only partly solubilized by the substrates, malate or oxaloacetate. High ionic strength treatments by either NaCl-carbonate or 3M KCl have a strong effect, but they also remove cytochrome c oxidase and rotenone-sensitive NADH-cytochrome c reductase, reputed inner membrane intrinsic enzymes, thus strongly damaging the inner membrane. After the action of phospholipase A from Naja Naja Venom, the residual activity is about twenty per cent and only phosphatidyl choline and phosphatidyl ethanolamine decreased significantly, the other phospholipids being unchanged. It is suggested that the enzyme is deeply buried in the membrane and mainly interacts with phosphatidyl choline.
苹果酸脱氢酶，一般认为是一种可溶性基质酶，但在猪心线粒体中，它也与内膜紧密相关。反复超声处理、水洗、冻融循环对于从内膜去除苹果酸脱氢酶活性的效果不太显著，无论采用何种处理方式，该酶活性仍然很高。苹果酸或草酰乙酸等底物只能使该活性部分溶解。用氯化钠 - 碳酸盐或3M氯化钾进行高离子强度处理有很强的效果，但同时也会去除细胞色素c氧化酶和鱼藤酮敏感的NADH - 细胞色素c还原酶，这两种酶被认为是内膜固有的酶，从而严重破坏内膜。经眼镜蛇毒磷脂酶A作用后，残余活性约为20%，只有磷脂酰胆碱和磷脂酰乙醇胺显著减少，其他磷脂则无变化。这表明该酶深深地埋在膜中，主要与磷脂酰胆碱相互作用。
