Nuclear catalyzed antibiotic free radical formation.
Nuclear catalyzed antibiotic free radical formation.
复制标题
核催化抗生素自由基形成。
作者：
N. Bachur;M. Gee;R. Friedman
从大鼠肝脏、心脏和肾脏分离的细胞核在还原型吡啶核苷酸 (NADPH) 和醌或醌亚胺抗生素（如阿霉素、柔红霉素、放线菌素 D、丝裂霉素 C 和链黑素）存在下催化耗氧。 NADPH 的 Km 和 Vmax 值为每毫克蛋白质每分钟 2.4 x 10(-3) M 和 3 x 10(-8) mol O2，抗生素的 Km 值范围为 1.4 x 10(-4) M 至 5.9 x 10(-6) M。 蒽环类抗生素的代谢，即还原糖苷酶反应，发生在反应混合物中所有氧气都被消耗掉。在反应过程中，可以通过电子顺磁推理光谱法检测阿霉素和柔红霉素的自由基种类。这些观察表明，一些细胞毒性抗生素可以在可能导致核 DNA 损伤的部位被激活为自由基状态。
Nuclei isolated from rat liver, heart, and kidney catalyze oxygen consumption in the presence of reduced pyridine nucleotide (NADPH) and quinone or quinone-imine antibiotics such as Adriamycin, daunorubicin, actinomycin D, mitomycin C, and streptonigrin. The Km and Vmax values for NADPH were 2.4 x 10(-3) M and 3 x 10(-8) mol O2 per min per mg protein and Km values for the antibiotics ranged from 1.4 x 10(-4) M to 5.9 x 10(-6) M. Metabolism of the anthracycline antibiotics, i.e., reductive glycosidase reaction, occurs in reaction mixtures after all oxygen is consumed. During the reaction, free-radical species of Adriamycin and daunorubicin are detectable by electron paramagnetic reasonance spectrometry. These observations indicate that some cytotoxic antibiotics can be activated to a free-radical state at the site where damage to nuclear DNA may result.