Woeltje K F, Kuwajima M, Foster D W, McGarry J D
J Biol Chem. 1987 Jul 15;262(20):9822-7.
Exposure of rat liver mitochondrial membranes to octyl glucoside, Triton X-100, or Tween 20 solubilized an active and tetradecylglycidyl-CoA (TG-CoA)-insensitive carnitine palmitoyltransferase (presumed to be carnitine palmitoyltransferase II). The residual membranes after octyl glucoside or Triton X-100 treatment were devoid of all transferase activity. By contrast, Tween 20-extracted membranes were still rich in transferase; this was completely blocked by TG-CoA and thus was presumed to be carnitine palmitoyltransferase I. The residual carnitine palmitoyltransferase activity disappeared from the membranes upon subsequent addition of octyl glucoside or Triton X-100 and could not be recovered in the supernatant fraction. Antibody raised against purified rat liver transferase II (Mr 80,000) recognized only this protein in immunoblots from untreated liver mitochondrial membranes containing both transferases I and II. Tween 20-extracted membranes, which contained only transferase I, did not react with the antibody. Purified transferase II from skeletal muscle (also of Mr 80,000) was readily recognized by the antiserum, suggesting antigenic similarity with the liver enzyme. These and other studies on the effects of detergents on the mitochondrial [3H]TG-CoA binding protein provide further support for the model of carnitine palmitoyltransferase proposed in the preceding paper. They suggest that: 1) carnitine palmitoyltransferases I and II in rat liver are immunologically distinct proteins; 2) transferase I is more firmly anchored into its membrane environment than transferase II; 3) association of carnitine palmitoyltransferase I with a membrane component(s) is necessary for catalytic activity. While carnitine palmitoyltransferase I is a different protein in liver and muscle, it seems likely that both tissues share the same transferase II.
将大鼠肝脏线粒体膜暴露于辛基葡糖苷、Triton X-100或吐温20中，可溶解一种活性的、对十四烷基缩水甘油辅酶A（TG-CoA）不敏感的肉碱棕榈酰转移酶（推测为肉碱棕榈酰转移酶II）。用辛基葡糖苷或Triton X-100处理后的残余膜没有任何转移酶活性。相比之下，用吐温20提取的膜仍然富含转移酶；这种转移酶完全被TG-CoA阻断，因此推测为肉碱棕榈酰转移酶I。随后加入辛基葡糖苷或Triton X-100后，膜上剩余的肉碱棕榈酰转移酶活性消失，且无法在上清液部分中恢复。针对纯化的大鼠肝脏转移酶II（分子量80,000）产生的抗体，在含有转移酶I和II的未处理肝脏线粒体膜的免疫印迹中仅识别出这种蛋白质。仅含有转移酶I的吐温20提取的膜与该抗体不发生反应。来自骨骼肌的纯化转移酶II（分子量也为80,000）很容易被抗血清识别，表明与肝脏酶具有抗原相似性。这些以及其他关于去污剂对线粒体[3H]TG-CoA结合蛋白影响的研究，为前文提出的肉碱棕榈酰转移酶模型提供了进一步的支持。它们表明：1）大鼠肝脏中的肉碱棕榈酰转移酶I和II是免疫上不同的蛋白质；2）转移酶I比转移酶II更牢固地锚定在其膜环境中；3）肉碱棕榈酰转移酶I与一种或多种膜成分的结合对于催化活性是必需的。虽然肝脏和肌肉中的肉碱棕榈酰转移酶I是不同的蛋白质，但这两种组织似乎共享相同的转移酶II。
