Fry M, Green D E
J Bioenerg Biomembr. 1981 Apr;13(1-2):61-87. doi: 10.1007/BF00744747.
Cytochrome oxidase has been resolved in acetic acid and high salt/detergent media. In 0.5% acetic acid, the smaller subunits of the enzyme are selectively extracted with retention of an insoluble protein fraction containing subunits I-IV, VII. This fraction retains all the heme and copper of the original enzyme in a spectrally unaltered state, and possesses enzymic activity comparable to the unresolved enzyme. The further removal of subunit IV from this fraction results in migration of heme and copper and modification of their spectral characteristics. Resolution of the enzyme in a high salt/detergent medium extracts smaller subunits (V-VII) together with subunit IV and some heme and copper. The heme associated with this enzymically active extract has spectral characteristics that are partially suggestive of heme a3. It is suggested that the fraction of subunits I-IV,VII, resolved in dilute acetic acid, may represent the limit of resolution of the cytochrome oxidase complex that remains actively and spectrally indistinguishable from the original enzyme.
细胞色素氧化酶已在乙酸和高盐/去污剂介质中被解析。在0.5%的乙酸中，该酶的较小亚基被选择性提取，同时保留了一个包含亚基I-IV、VII的不溶性蛋白质部分。这个部分保留了原始酶的所有血红素和铜，且其光谱状态未改变，并且具有与未解析的酶相当的酶活性。从这个部分进一步去除亚基IV会导致血红素和铜的迁移以及它们光谱特征的改变。在高盐/去污剂介质中解析该酶会提取出较小的亚基（V-VII）以及亚基IV和一些血红素和铜。与这种具有酶活性的提取物相关的血红素具有部分暗示血红素a3的光谱特征。有人提出，在稀乙酸中解析出的亚基I-IV、VII部分可能代表了细胞色素氧化酶复合物分辨率的极限，该复合物在活性和光谱上与原始酶无法区分。
