Retention of enzyme activity by detergent-solubilized sarcoplasmic Ca2+ -ATPase.
Retention of enzyme activity by detergent-solubilized sarcoplasmic Ca2+ -ATPase.
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去污剂溶解的肌浆 Ca2-ATP 酶保留酶活性。
DOI：
10.1021/bi00656a014
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发表时间：
1976
期刊：
影响因子：
2.9
通讯作者：
Charles Tanford
中科院分区：
文献类型：
--
作者：
M. le Maire;Jesper V. Moeller;Charles Tanford
肌浆网Ca ~（2+）激活的ATP酶在某些非离子去污剂存在下能在真溶液中存在，并保持酶活性数天。即使在大量过量的去污剂存在下，可溶性活性颗粒仍保留每摩尔多肽链约30摩尔磷脂，这表明蛋白质和脂质之间存在相对强的吸引力，正如其他实验室的先前工作已经表明的那样。脱氧胆酸盐在去除蛋白质结合的脂质方面比非离子型去污剂有效得多，并且当以增溶浓度使用时，完全去脂并使ATP酶失活。初步的分子量测量表明，Ca 2 + -ATP酶作为低聚物存在于天然膜中：吐温80中的完全活性酶具有约400 000的最小蛋白质分子量，对应于ATP酶多肽链的三聚体或四聚体，并且甚至脱氧胆酸盐中的失活酶也含有大量二聚体蛋白。
The Ca2+ -activated ATPase of sarcoplasmic reticulum can exist in true solution in the presence of some nonionic detergents, with retention of enzymatic activity for several days. The soluble active particles retain about 30 mol of phospholipid per mol of polypeptide chain even in the presence of a large excess of detergent, indicating the existence of relatively strong attractive forces between protein and lipid, as previous work from other laboratories has already suggested. Deoxycholate is much more effective than nonionic detergents in removing protein-bound lipid and, when used at solubilizing concentrations, completely delipidates and inactivates the ATPase. Preliminary molecular weight measurements indicate that the Ca2+ -ATPase exists as an oligomer in the native membrane: fully active enzyme in Tween 80 has a minimal protein molecular weight of about 400 000, corresponding to a trimer or tetramer of the ATPase polypeptide chain, and even the inactive enzyme in deoxycholate contains a substantial fraction of dimeric protein.