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.
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机译：研究了控制荚膜组织胞浆酵母细胞内过氧化氢酶水平的因素。在整个细胞中只能检测到总过氧化氢酶活性的一小部分。大量的活性显示在无细胞提取物中或在丙酮渗透的细胞中。葡萄糖和氧气调节酶的形成。在荚膜荚膜梭菌菌株之间过氧化氢酶水平存在较大的一致差异。菌株对H 2 O 2毒性的敏感性也显着变化。在菌株的无细胞提取物中未检测到过氧化物酶活性。对H2O2的抵抗力与过氧化氢酶水平不符。菌株之间H2O2的敏感性和毒力之间没有明显的相关性。
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