Mileykovskaya E I, Abuladze A N, Kormer S S, Ostrovsky D N
Eur J Biochem. 1987 Sep 1;167(2):367-70. doi: 10.1111/j.1432-1033.1987.tb13346.x.
Radiation inactivation analysis gave the target sizes of 176 +/- 5 kDa and 275 +/- 33 kDa for ATPase from anaerobic Lactobacillus casei and aerobic Micrococcus luteus bacteria respectively. The values are close to the known molecular masses of the enzymes. Thus, to function the L. casei ATPase, like the F1-ATPases, requires a complete structure composed of all the enzyme subunits. L. casei ATPase is inhibited by 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole owing to modification of an amino acid residue(s) with pK greater than 8.5. L. casei ATPase consists of six identical subunits and differs from alpha 3 beta 3 gamma delta epsilon-type F1-ATPases in a number of catalytic properties. Namely, ATP hydrolysis under the 'unisite' conditions proceeds at a relatively high rate suggesting the absence of cooperative interactions between the catalytic sites. Contrary to mitochondrial F1-ATPase. L. casei ATPase does not form an inactive complex with ADP. These findings imply essential differences in the operating mechanism for L. casei ATPase and F1 ATPase.
辐射失活分析表明，来自厌氧干酪乳杆菌和好氧藤黄微球菌的ATP酶的靶标大小分别为176±5 kDa和275±33 kDa。这些值与已知的酶分子量相近。因此，与F1 - ATP酶一样，干酪乳杆菌ATP酶发挥功能需要由所有酶亚基组成的完整结构。由于pK大于8.5的氨基酸残基发生修饰，干酪乳杆菌ATP酶受到4 - 氯 - 7 - 硝基苯并 - 2 - 恶唑 - 1,3 - 二氮杂茂的抑制。干酪乳杆菌ATP酶由六个相同的亚基组成，在一些催化特性上与α3β3γδε型F1 - ATP酶不同。具体而言，在“单位点”条件下的ATP水解以相对较高的速率进行，这表明催化位点之间不存在协同相互作用。与线粒体F1 - ATP酶相反，干酪乳杆菌ATP酶不会与ADP形成无活性复合物。这些发现意味着干酪乳杆菌ATP酶和F1 ATP酶的作用机制存在本质差异。
