Specificity and binding affinity of phospholipids to the high-affinity cardiolipin sites of beef heart cytochrome c oxidase.
Specificity and binding affinity of phospholipids to the high-affinity cardiolipin sites of beef heart cytochrome c oxidase.
复制标题
磷脂对牛心细胞色素 c 氧化酶高亲和力心磷脂位点的特异性和结合亲和力。
DOI：
10.1021/bi00530a031
复制
发表时间：
1982
期刊：
影响因子：
2.9
通讯作者：
Robinson,NC
中科院分区：
文献类型：
--
作者：
Robinson,NC
Neal C. Robinson abstract: Beef heart lipid-depleted cytochrome c oxidase, containing only 50% of the two to three essential high-affinity cardiolipin molecules per heme aa2 complex, was used to study the phospholipid requirements of this enzyme. The lipid-de-pleted complex had two-thirdsof the electron transport activity as enzyme containing a full complement of essential cardiolipin (diphosphatidylglycerol or DPG) when it was assayed in Tween 80. However, incubation of the lipid-depleted enzyme with DPG in the presence of 1% Triton X-100followed by a 140-fold dilution of the reconstituted complex into Tween 80 re-stored 100% of the initial activity. Similar incubations of the lipid-depleted enzyme with phosphatidylethanolamine, phos-phatidylglycerol, phosphatidylserine, or phosphatidic acid did not stimulate the enzymatic activity in Tween 80 more than 5-10%. In the presence of 1% Triton X-100, bovine DPG (90% Cl8: 2) reassociated with the vacant high-affinity sites with an apparent dissociation constant of 5 µ based upon (Cytochrome c oxidase, a multisubunit intrinsic membrane protein complex, spans the inner mitochondrial membrane and, therefore, contacts a layer of boundary phospholipids (PL). 1 Not all of these boundary layer PL’s are removed from the protein during its solubilization by nondenaturing detergents and subsequent purification. Depending upon the method of
