East J M, Melville D, Lee A G
Biochemistry. 1985 May 21;24(11):2615-23. doi: 10.1021/bi00332a005.
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 two 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 degrees C. A minimum number of annular phospholipid sites of 32 and 22 are calculated at 0 and 37 degrees C, respectively.
一种自旋标记的磷脂被用于研究肌肉肌浆网（Ca2 +，Mg2 +）-ATP酶中的脂-蛋白相互作用。一种新颖的零方法被用于将复合电子自旋共振谱分解为两个成分，分别代表固定环境和流动环境的特征。基于随机混合模型的计算表明，在这些系统中蛋白质-蛋白质相互作用相对较少，并且固定化脂质并不代表被困在蛋白质之间的脂质，而是代表腺苷三磷酸酶脂-蛋白界面处的环形磷脂。随着温度升高，固定化脂质数量的明显减少表明其与本体和环之间的脂质交换一致，其特征是在37℃时交换时间为10（-7）秒。分别计算出在0℃和37℃时环形磷脂位点的最小数量为32和22。
