Dean G E, Nelson P J, Agnew W S, Rudnick G
Biochemistry. 1987 Apr 21;26(8):2301-5. doi: 10.1021/bi00382a034.
We have determined the hydrodynamic properties of detergent-solubilized ATPase, which is coupled to H+ pumping in bovine adrenal chromaffin granules, by sedimentation equilibrium centrifugation and gel permeation chromatography. The protein solubilized with detergent containing phosphatidylserine sediments as a particle of 264,000 daltons and partial specific volume 0.829 cm3/g. Assuming a protein v of 0.73 and using the v measured for detergent and lipid mixed micelles of 0.93 cm3/g, we calculated that the protein component has a mass of 134,000 daltons and that the equivalent of approximately 1.5 micelles of detergent are bound per particle. The particle exhibits a Stokes radius of 43 A, which, together with the calculated particle volume, indicates an axial ratio close to 1. We conclude that the ATPase is an intrinsic membrane protein with a structure very different from that of mitochondrial F1F0 ATPase.
我们已通过沉降平衡离心法和凝胶渗透色谱法测定了去污剂增溶的ATP酶的流体动力学性质，该ATP酶与牛肾上腺嗜铬颗粒中的H⁺泵浦相关联。用含有磷脂酰丝氨酸的去污剂增溶的蛋白质以264,000道尔顿的颗粒形式沉降，比容为0.829 cm³/g。假设蛋白质的偏比容v为0.73，并使用测得的去污剂和脂质混合胶束的偏比容v为0.93 cm³/g，我们计算出蛋白质组分的质量为134,000道尔顿，且每个颗粒结合约1.5个去污剂胶束当量。该颗粒的斯托克斯半径为43 Å，这与计算出的颗粒体积一起表明轴比接近1。我们得出结论，该ATP酶是一种内在膜蛋白，其结构与线粒体F₁F₀ ATP酶的结构非常不同。
