Rauchová H, Ledvinková J, Kalous M, Drahota Z
Institute of Physiology, Academy of Sciences of the Czech Republic, Prague.
Int J Biochem Cell Biol. 1995 Mar;27(3):251-5. doi: 10.1016/1357-2725(94)00083-n.
Peroxidation of membrane phospholipids is accompanied by alteration of the structural and functional characteristics of membranes. Lipid peroxidation changes the activities of various enzymes. The present study evaluates the effect of lipid peroxidation on the activity of various ATPases localized on kidney membranes. Our experiments were performed on crude preparation of rat kidney membranes which were exposed to Fe2+.ADP/NADPH-induced lipid peroxidation. The extent of peroxidation was estimated by measuring the thiobarbituric acid-reactive substances. Simultaneously the activities of different ATPases were determined and divided according to their ouabain sensitivity and Mg2+ dependency. We found that 10 min incubation of isolated rat kidney membranes at 37 degrees C with inductors of lipid peroxidation increased the production of thiobarbituric acid-reactive substances from 1.10 +/- 0.26 to 7.72 +/- 2.55 nmol malondialdehyde/mg prot. (+/- SD, n = 4). Under these conditions total ATPase activity was decreased from 681 +/- 77 to 507 +/- 82, ouabain-sensitive Mg(2+)-dependent ATPase (Na+,K(+)-ATPase) activity from 249 +/- 54 to 81 +/- 21 and ouabain-insensitive Mg(2+)-dependent activity from 287 +/- 48 to 173 +/- 58 whereas apparently Mg(2+)-independent ATPase activity was increased from 145 +/- 37 to 253 +/- 42 nmoles P/min/mg prot. (+/- SD, n = 4). The study indicates different mechanisms by which lipoperoxides affect the function of membrane-bound ATPases activities. It is concluded that the ATPases activities are changed during lipid peroxide formation.
膜磷脂的过氧化伴随着膜的结构和功能特性的改变。脂质过氧化会改变各种酶的活性。本研究评估脂质过氧化对定位于肾膜上的各种ATP酶活性的影响。我们的实验是在大鼠肾膜粗制品上进行的，将其暴露于Fe2 +、ADP/NADPH诱导的脂质过氧化环境中。通过测量硫代巴比妥酸反应性物质来估计过氧化程度。同时测定不同ATP酶的活性，并根据它们对哇巴因的敏感性和对Mg2 +的依赖性进行分类。我们发现，将分离的大鼠肾膜在37℃下与脂质过氧化诱导剂孵育10分钟，硫代巴比妥酸反应性物质的产生量从1.10±0.26增加到7.72±2.55 nmol丙二醛/毫克蛋白（±标准差，n = 4）。在这些条件下，总ATP酶活性从681±77降至507±82，对哇巴因敏感的Mg(2 +)依赖性ATP酶（Na +，K( +)-ATP酶）活性从249±54降至81±21，对哇巴因不敏感的Mg(2 +)依赖性活性从287±48降至173±58，而明显不依赖Mg(2 +)的ATP酶活性从145±37增加到253±42 nmol磷/分钟/毫克蛋白（±标准差，n = 4）。该研究表明脂质过氧化物影响膜结合ATP酶活性功能的不同机制。得出的结论是，在脂质过氧化物形成过程中ATP酶活性发生了变化。
