MOLECULAR-WEIGHT AND HYDRODYNAMIC PARAMETERS OF THE ADENOSINE 5'-DIPHOSPHATE-ADENOSINE 5'-TRIPHOSPHATE CARRIER IN TRITON X-100
MOLECULAR-WEIGHT AND HYDRODYNAMIC PARAMETERS OF THE ADENOSINE 5'-DIPHOSPHATE-ADENOSINE 5'-TRIPHOSPHATE CARRIER IN TRITON X-100
复制标题
DOI：
10.1021/bi00544a024
复制
发表时间：
1980-01-01
期刊：
影响因子：
2.9
通讯作者：
KLINGENBERG, M
中科院分区：
文献类型：
--
作者：
HACKENBERG, H;KLINGENBERG, M
通过蔗糖梯度沉淀、凝胶过滤和超离心分析，研究了牛心脏线粒体中triton溶解的ADP-ATP载体羧基atractyate （CAT）复合物。测量Triton结合和沉降速度是不可能的，除非通过额外的蔗糖密度梯度离心分离多余的Triton和磷脂。利用分析型超离心机的吸收光学系统，分析了由蛋白质、结合Triton、自由Triton胶束和Triton单体组成的多组分体系。分离的蛋白结合了大量的Triton （1.5 g/g蛋白质）和磷脂（0.25 g/g蛋白质），这是固有膜蛋白所期望的。在蔗糖梯度和分析型超离心机中测定的沉降效率为20，w = 3.9倍。10 - 13。由斯托克斯半径（RS = 65 . ang）计算得到的扩散系数为（3.4 ~ 3.5）倍。这两种情况都是10- 7cm2 /s。部分比体积。hivin。从单个组分的分数和在不同密度溶液中的沉降平衡测量（.hivin）来评估蛋白质-氚-磷脂复合物的v*。V * = 0.845 cm3/g)。MW由Svedberg方程（M* 184,000）和沉降平衡测量值（M* 172,000）计算得出。在减去结合的Triton和磷脂后，发现蛋白质部分的分子量为67,000(63,000)，表明Triton溶解的cat -蛋白复合物以由2个肽亚基组成的二聚体存在。从几何角度考虑，得出的结论是，蛋白质完全包裹在一个椭球胶束。150海卫一和apprx。16个磷脂分子。
The Triton-solubilized ADP-ATP carrier from beef heart mitochondria was studied as the carboxyatractylate (CAT) complex by sedimentation in sucrose gradients, gel filtration, and analytical ultracentrifugation. The measurements of Triton binding and sedimentation velocity were not possible unless excess Triton and phospholipid were separated by an additional sucrose density gradient centrifugation. The absorption optical system of the analytical ultracentrifuge was used to analyze a multicomponent system consisting of protein, bound Triton, free Triton micelles and Triton monomers. The isolated protein binds high amounts of Triton (1.5 g/g of protein) and phospholipid (0.25 g/g of protein) as would be expected for an intrinsic membrane protein. The sedimentation ocefficient, measured on sucrose gradients and in the analytical ultracentrifuge, was s20,w = 3.9 .times. 10-13 s. The diffusion coefficient, calculated from the Stokes'' radius (RS = 65 .ANG.) and determined in the analytical ultracentrifuge, was (3.4-3.5) .times. 10-7 cm2/s in both cases. The partial specific volume .hivin.v* of the protein-Triton-phospholipid complex was evaluated from the fractions of the individual components and from sedimentation equilibrium measurements in solutions of different densities (.hivin.v* = 0.845 cm3/g). The MW was calculated from the Svedberg equation (M* 184,000) and from sedimentation equilibrium measurements (M* 172,000). After subtraction of the bound Triton and phospholipid, MW 67,000 (63,000) was found for the protein moiety, indicating that the Triton-solubilized CAT-protein complex exists as a dimer composed of 2 peptide subunits. From geometrical considerations it is concluded that the protein is completely enveloped in an ellipsoid micelle of .apprx. 150 Triton and .apprx. 16 phospholipid molecules.