摘要
外源性硫化物可通过抑制或阻断线粒体电子传递经典途径而对生物体产生损伤甚至致死,交替氧化酶(Alternative Oxidase,AOX)是线粒体硫化物氧化电子传递分支途径中的1个关键酶。为了研究硫化物环境中单环刺螠的生存对策,本文利用间接竞争性ELISA和酶活性分析等技术检测了单环刺螠在硫化物应激前后中肠和后肠中AOX的蛋白含量以及活性的变化。结果显示:在未处理的单环刺螠中,后肠的AOX蛋白含量和酶活性均高于中肠。当单环刺螠暴露在硫化物(50和150μmol·L-1)环境中时,2个器官的AOX含量和酶活性水平均随着硫化物浓度的提高和暴露时间的延长而提高,并且150μmol·L-1硫化物处理组的单环刺螠2个器官AOX蛋白含量和酶活性普遍高于相同处理时间下的50μmol·L-1组。结合已报道的单环刺螠硫化物应激下细胞色素c氧化酶活性的变化,提出单环刺螠体内存在线粒体电子传递分支途径;提高组织线粒体中AOX活性是其应对环境硫化物毒性的对策之一。
Exogenous sulfide can damage or even kill the organism by inhibiting or blocking classical pathway of mitochondrial electron transport （MET）, while alternative oxidase as a key enzyme, conducts a branch pathway of the sulfide oxidation MET. In order to study the animal＇s survival countermeasures to sulfide environment, in this study we determined the protein expression and activity change of alternative oxidase （AOX） in the mid-gut and hindgut of Urechis unicinctus before and after sulfide stress by indirect competitive ELISA, and AOX enzyme activity analysis. The result showed, it was detected that the presence of AOX protein and enzyme activity in mid-gut and hindgut, which were higher in hindgut than mid-gut. When exposed at 50 and 150μmol · L^-1 sulfide, the AOX protein amount and enzyme activity in mid-gut and hindgut both increased with elevation of sulfide concentration and delay of sulfide exposure time. AOX expression and activity in the 2 tissues exposed in 150 μmol · L^-1 is almost higher than that of 50 μmol · L^-1. Combining with changes of activity of cytochrome c oxidase which has been reported in U. unicinctus exposed to sulfide, we discussed the role of AOX in 2 tissues of U. unicinctus exposed to different concentrations of sulfide, and suggested that an AOX branch pathway of MET existed in U. unicinctus, and the increase of the AOX activity was one of strategy for response to the toxicity of environment sulfide in the worm.
出处
《中国海洋大学学报（自然科学版）》
CAS
CSCD
北大核心
2015年第2期66-71,共6页
Periodical of Ocean University of China
基金
国家自然科学基金项目(31072191)资助
关键词
单环刺螠
交替氧化酶
硫化物
线粒体
电子传递链
Urechis unicinctus
alternative oxidase
sulfide
mitochondria
electrons transport chain
