Howard D H
Infect Immun. 1983 Mar;39(3):1161-6. doi: 10.1128/iai.39.3.1161-1166.1983.
Factors which control the levels of catalase within yeast cells of Histoplasma capsulatum were studied. Only a small fraction of the total catalase activity could be detected in whole cells. The bulk of the activity was revealed in cell-free extracts or in cells permeabilized with acetone. The formation of the enzyme was regulated by glucose and by oxygen. There were large, consistent differences in the levels of catalase among strains of H. capsulatum. The sensitivity of the strains to H2O2 toxicity also varied remarkably. Peroxidase activity could not be detected in cell-free extracts of the strains. Resistance to H2O2 did not correspond to levels of catalase. There was no obvious correlation of H2O2 sensitivity and virulence among the strains.
对荚膜组织胞浆菌酵母细胞内过氧化氢酶水平的控制因素进行了研究。在完整细胞中仅能检测到总过氧化氢酶活性的一小部分。大部分活性在无细胞提取物或用丙酮通透处理的细胞中显现出来。该酶的形成受葡萄糖和氧气调节。荚膜组织胞浆菌不同菌株间过氧化氢酶水平存在巨大且一致的差异。各菌株对H2O2毒性的敏感性也有显著差异。在这些菌株的无细胞提取物中未检测到过氧化物酶活性。对H2O2的抗性与过氧化氢酶水平不对应。各菌株间H2O2敏感性与毒力无明显相关性。
