EXCHANGE-RATES AND NUMBERS OF ANNULAR LIPIDS FOR THE CALCIUM AND MAGNESIUM-ION DEPENDENT ADENOSINE-TRIPHOSPHATASE
EXCHANGE-RATES AND NUMBERS OF ANNULAR LIPIDS FOR THE CALCIUM AND MAGNESIUM-ION DEPENDENT ADENOSINE-TRIPHOSPHATASE
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DOI：
10.1021/bi00332a005
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发表时间：
1985-01-01
期刊：
影响因子：
2.9
通讯作者：
LEE, AG
中科院分区：
文献类型：
--
作者：
EAST, JM;MELVILLE, D;LEE, AG
用自旋标记的磷脂研究了肌浆网(Ca~(2+)，Mg~(2+))-ATPase中的脂-蛋白相互作用。用一种新的零方法将复合电子自旋共振谱分解成两个组分，具有固定和移动环境的特点。基于随机混合模型的计算表明，在这些系统中，蛋白质-蛋白质相互作用将相对罕见，并且固定化的脂类并不代表被困在蛋白质之间的脂类，而是三磷酸腺苷酶的脂蛋白界面上的环状磷脂。随着温度的升高，固定化脂质的量明显减少，这与块状和环状之间的脂肪交换是一致的，交换时间为10-7 S，温度为37度。C.在0度下计算出环状磷脂位置的最小数目为32和22。37度。C。
A spin-labeled phospholipid is used to study lipid-protein interactions in the(Ca2+, Mg2+)-ATPase of sarcoplasmic reticulum from muscle. A novel null method is used to decompose composite electron spin resonance spectra into 2 components, characteristic of immobilized and mobile environments. Calculations based on a random mixing model suggest that protein-protein interactions will be relatively rare in these systems, and that the immobilized lipid does not represent lipid trapped between proteins, but rather represents annular phospholipid at the lipid-protein interface of the adenosinetriphosphatase. The apparent decrease in the amount of immobilized lipid with increasing temperature is shown to be consistent with lipid exchange between bulk and annulus, characterized by an exchange time of 10-7 s at 37.degree. C. A minimum number of annular phospholipid sites of 32 and 22 are calculated at 0.degree. and 37.degree. C, respectively.