Bandopadhyay S, Ray T K
Prep Biochem. 1986;16(1):21-32. doi: 10.1080/00327488608062456.
An endogenous protein activator (AF) responsible for the activation of the gastric H+,K+-ATPase system, identified recently as the biochemical mechanism for the transport of H+, has been purified to homogeneity and partially characterized. The purification procedure (at 0-4 degrees C) involves simultaneous concentration and dialysis of the cytosolic fraction from dog fundic cells under negative pressure, pH 4.8 precipitation and two consecutive gel filtration steps on sephacryl S-200 columns. The highly purified and active AF is a protein of 80 Kd consisting of two identical subunits of 40 Kd each. The AF not only stimulates the gastric H+,K+-ATPase activity but also greatly enhances the rate of ATPase dependent proton pumping inside gastric microsomal vesicles. The data clearly suggest an important regulatory role of the cytosolic AF in the gastric HCl secretory process.
一种负责激活胃H⁺，K⁺ - ATP酶系统的内源性蛋白质激活剂（AF），最近被确定为H⁺转运的生化机制，已被纯化至同质并进行了部分特性鉴定。纯化过程（在0 - 4℃）包括在负压下对犬胃底细胞的胞质部分进行同时浓缩和透析、pH 4.8沉淀以及在Sephacryl S - 200柱上进行两个连续的凝胶过滤步骤。高度纯化且有活性的AF是一种80 Kd的蛋白质，由两个相同的40 Kd亚基组成。AF不仅刺激胃H⁺，K⁺ - ATP酶活性，还极大地提高了胃微粒体囊泡内依赖ATP酶的质子泵浦速率。数据清楚地表明胞质AF在胃盐酸分泌过程中具有重要的调节作用。
