Palop A, Rutherford G C, Marquis R E
Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, NY 14642-8672, USA.
Can J Microbiol. 1998 May;44(5):465-70.
The organic hydroperoxides t-butyl hydroperoxide, cumene hydroperoxide, and peracetic acid were found to act similarly to hydrogen peroxide in causing inactivation of enzymes within intact spores of bacillus megaterium ATCC 19213 concomitant with mortality. Spores treated with lethal levels of the agents were germinated and permeabilized for enzyme assays. The hierarchy of sensitivities among enolase, glucose-6-phosphate dehydrogenase (G6Pdh), and pyruvate kinase to inactivation varied somewhat with the specific hydroperoxide used, possibly because of the differences in the types of radicals generated. However, each agent inactivated each of the enzymes, albeit at different rates. Comparative assessments of enzyme inactivation by lethal levels of H2O2 or by moist heat showed that some enzymes, such as G6Pdh, are highly sensitive to inactivation, while others, such as ATPases, are much more resistant. The enzymes G6Pdh and aldolase were highly sensitive to hydroperoxide inactivation and also to moist heat, while pyruvate kinase was much more sensitive to hydroperoxides than to moist heat. Our overall interpretation of the findings is that hydroperoxides and moist heat can produce cumulative damage to sensitive enzymes within spores, which progressively diminishes the capacities of the cells to undergo the outgrowth required for return to vegetative life.
研究发现，有机氢过氧化物叔丁基过氧化氢、异丙苯过氧化氢和过氧乙酸在导致巨大芽孢杆菌ATCC 19213完整芽孢内的酶失活并伴随死亡率方面，其作用与过氧化氢相似。用致死剂量的这些试剂处理过的芽孢会萌发并透化，以便进行酶分析。烯醇化酶、葡萄糖-6-磷酸脱氢酶（G6Pdh）和丙酮酸激酶对失活的敏感性顺序，会因所使用的特定氢过氧化物而有所不同，这可能是由于所产生的自由基类型不同。然而，每种试剂都会使每种酶失活，尽管失活速率不同。对致死剂量的H2O2或湿热导致的酶失活进行的比较评估表明，某些酶，如G6Pdh，对失活高度敏感，而其他酶，如ATP酶，则更具抗性。G6Pdh和醛缩酶对氢过氧化物失活以及湿热都高度敏感，而丙酮酸激酶对氢过氧化物的敏感性比对湿热的敏感性高得多。我们对这些发现的总体解释是，氢过氧化物和湿热会对芽孢内的敏感酶造成累积损伤，从而逐渐降低细胞恢复营养生活所需的生长能力。
