Edwards C, Spode J A, Jones C W
Biochem J. 1978 May 15;172(2):253-60. doi: 10.1042/bj1720253.
The properties of Alcaligenes eutrophus ATPase (adenosine triphosphatase) were investigated by using subcellular fractions prepared from cells growing in exponential and synchronous cultures. Both the soluble and membrane-bound forms of the ATPase were inhibited non-competitively (K(i) 142mum) by Nbf-Cl (4-chloro-7-nitrobenzofurazan), whereas only the membrane-bound enzyme was inhibited (non-competitive; K(i) 750mum) by NN'-dicyclohexylcarbodi-imide. Neither the activity of the ATPase nor its sensitivity to these two inhibitors varied during exponential growth. However, marked variations in ATPase activity were observed during synchronous growth, which were characterized by maxima at approx. 0.4 and 0.9 of a cell cycle and minima at approx. 0.1 and 0.6 of a cycle. Sensitivity to Nbf-Cl and NN'-dicyclohexylcarbodi-imide also varied during the cell cycle; maximum inhibition by the former occurred at approx. 0.4 and 0.9 of a cell cycle, whereas maximum inhibition by the latter was located at approx. 0.1 and 0.6 of a cell cycle. Proton conductance by whole cells was also periodic during the cell cycle, the lowest rates occurring at approx. 0.15 and 0.55 of a cycle and the highest rates at approx. 0.4 and 0.9 of a cycle, but -->H(+)/O quotients for the oxidation of endogenous substrates remained relatively constant and indicated the presence of four proton-translocating respiratory segments throughout the cell cycle. These results are discussed in terms of ATPase and respiratory-chain structure and function during the cell cycle of Alcaligenes eutrophus.
利用从指数生长和同步培养的细胞中制备的亚细胞级分，对真养产碱杆菌ATP酶（腺苷三磷酸酶）的性质进行了研究。ATP酶的可溶性形式和膜结合形式均受到Nbf-Cl（4-氯-7-硝基苯并呋咱）的非竞争性抑制（抑制常数K(i)为142μM），而只有膜结合酶受到NN'-二环己基碳二亚胺的抑制（非竞争性；抑制常数K(i)为750μM）。在指数生长期间，ATP酶的活性及其对这两种抑制剂的敏感性均未发生变化。然而，在同步生长期间观察到ATP酶活性有明显变化，其特征是在细胞周期的约0.4和0.9处出现最大值，在约0.1和0.6处出现最小值。对Nbf-Cl和NN'-二环己基碳二亚胺的敏感性在细胞周期中也有所变化；前者的最大抑制作用发生在细胞周期的约0.4和0.9处，而后者的最大抑制作用位于细胞周期的约0.1和0.6处。全细胞的质子传导在细胞周期中也是周期性的，最低速率出现在细胞周期的约0.15和0.55处，最高速率出现在约0.4和0.9处，但是内源性底物氧化的H(+)/O商相对保持恒定，表明在整个细胞周期中存在四个质子转运呼吸段。根据真养产碱杆菌细胞周期中ATP酶和呼吸链的结构与功能对这些结果进行了讨论。
