Lund H
Biochim Biophys Acta. 1987 Mar 13;918(1):67-75. doi: 10.1016/0005-2760(87)90010-5.
Rat liver mitochondria were preextracted with Triton X-100 in the absence of salts to remove malonyl-CoA-insensitive carnitine palmitoyltransferase. From the remaining membrane residues a malonyl-CoA-sensitive enzyme was solubilized with octyl glucopyranoside in the presence of KCl. Significant enzyme activity, [2-14C]malonyl-CoA binding and malonyl-CoA inhibition of this enzyme was present only after removal of detergent by precipitation with poly(ethylene glycol). The enzyme activity was rapidly lost in the solubilized form. High concentrations of glycerol protected the enzyme. The alkylating irreversible inhibitor, S-(4-bromo-2,3-dioxobutyl)-CoA, strongly inhibited the malonyl-CoA-sensitive enzyme in the membrane residues. The enzyme was protected against this inhibitor by malonyl-CoA and palmitoyl-CoA. The more loosely membrane-bound malonyl-CoA-insensitive enzyme failed to bind malonyl-CoA, was stable in the presence of detergents and was not inhibited by S-(4-bromo-2,3-dioxobutyl)-CoA. It is suggested that two different carnitine palmitoyltransferase proteins exist in the inner mitochondrial membrane and that the detergent-labile malonyl-CoA-sensitive enzyme is the less easily extracted of the two.
大鼠肝脏线粒体在无盐条件下用 Triton X - 100 进行预提取，以去除对丙二酰辅酶 A 不敏感的肉碱棕榈酰转移酶。从剩余的膜残余物中，在 KCl 存在的情况下，用辛基吡喃葡萄糖苷溶解出一种对丙二酰辅酶 A 敏感的酶。只有在用聚乙二醇沉淀去除去污剂后，该酶才表现出显著的酶活性、[2 - 14C]丙二酰辅酶 A 结合以及丙二酰辅酶 A 对其的抑制作用。酶活性在溶解形式下会迅速丧失。高浓度的甘油可保护该酶。烷基化不可逆抑制剂 S - (4 - 溴 - 2,3 - 二氧代丁基) - 辅酶 A 强烈抑制膜残余物中对丙二酰辅酶 A 敏感的酶。丙二酰辅酶 A 和棕榈酰辅酶 A 可保护该酶免受此抑制剂的影响。与膜结合较松散的对丙二酰辅酶 A 不敏感的酶不能结合丙二酰辅酶 A，在去污剂存在下稳定，且不受 S - (4 - 溴 - 2,3 - 二氧代丁基) - 辅酶 A 的抑制。有人提出线粒体内膜中存在两种不同的肉碱棕榈酰转移酶蛋白，且对去污剂不稳定的对丙二酰辅酶 A 敏感的酶是这两种蛋白中较难提取的一种。
