Structural role of phospholipids in ubiquinol-cytochrome c reductase.
Structural role of phospholipids in ubiquinol-cytochrome c reductase.
复制标题
磷脂在泛醇细胞色素 c 还原酶中的结构作用。
作者：
Yu,CA;Yu,L
Chang-An Yu* and Linda Yu abstract: The role of phospholipids in ubiquionol-cytochrome c reductase has been studied by the following methods:(1) removal and restoration of phospholipids,(2) circular dichroism measurements, and (3) phospholipaseA2 treatment. Over 90% of the phospholipids in the cytochrome b-cl III complex (a highly purified ubiquinol-cytochrome c reductase) can be removed by repeated precipitation with ammonium sulfate in the presence of 0.5% sodium cholate. The delipidated enzyme complex is inactive. Full restoration of enzymatic activity can only be achieved with a freshly prepared delipi-dated enzyme complex, made in the presence of 20% glycerol. As the age of the delipidated enzyme increased, theamount of activity restored decreased and the incubation time required to reach maximal activity increased. Removal of phospholipids from the cytochrome bC\III complex resulted in an immediate decrease of~ 15% in molar ellipticities in both the far-UV and the Soret regions. A further decrease in ellip-ticities was observed uponincubation of the delipidated enzyme at 0 C in 50 mM phosphate buffer, pH 7.4. Replenishing phospholipids to the delipidated enzyme complex restored enzymatic activity and the molar ellipticity in both regions. The absolute requirement for phospholipids in the cytochrome b-Ci III complex was also demonstrated by treatment of the enzyme with purified phospholipase A2. Theinactivation of the cytochrome b-ct III complex by phospholipase A2 was not prevented by the presence of excess exogenous ubiquinone but was prevented by the presence of ethylenediaminetetracetic acid (EDTA). The enzymatic activity of the phospholipase A2 treated complex is fully restorable upon the addition of
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磷脂对细胞色素氧化还原电位和酶性质的影响b．
影响因子：
3.9
作者：
C. Yu;L. Yu;T. King
通讯作者：
T. King
DOI：
10.1016/s0021-9258(19)41825-5
发表时间：
1975
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
C. Yu;L. Yu;T. King
通讯作者：
T. King
DOI：
10.1016/s0021-9258(19)63284-9
发表时间：
1961
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
T. Yonetani
通讯作者：
T. Yonetani
影响因子：
2.9
作者：
DAVIS, JG;MAPES, CJ;DONOVAN, JW
通讯作者：
DONOVAN, JW
可溶性细胞色素 b-c1 复合物和琥珀酸-细胞色素 c 还原酶的重建。
DOI：
10.1016/s0021-9258(19)42407-1
发表时间：
1974
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
C. Yu;L. Yu;T. King
通讯作者：
T. King