INTERACTION OF AZOLE ANTIFUNGAL ANTIBIOTICS WITH CYTOCHROME P-450-DEPENDENT 14-ALPHA-STEROL DEMETHYLASE PURIFIED FROM CANDIDA-ALBICANS
INTERACTION OF AZOLE ANTIFUNGAL ANTIBIOTICS WITH CYTOCHROME P-450-DEPENDENT 14-ALPHA-STEROL DEMETHYLASE PURIFIED FROM CANDIDA-ALBICANS
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DOI：
10.1042/bj2660475
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发表时间：
1990-03-01
影响因子：
4.1
通讯作者：
ADAMS, DJ
中科院分区：
文献类型：
--
作者：
HITCHCOCK, CA;DICKINSON, K;ADAMS, DJ
唑类抗真菌抗生素与纯化白色念珠菌细胞色素p -450依赖性14 - α的相互作用。-甾醇，去甲基化酶（P-450DM）测定分光光度法和抑制酶活性。酮康唑和ICI 153066（三唑衍生物）与铁细胞色素形成低自旋配合物并诱导II型差异光谱。这些光谱表明，在P-450DM血红素的第6配位位置上，唑基团之间存在相互作用。两种氮唑均抑制CO与二亚硫酸钠还原亚铁细胞色素的结合，并通过与细胞色素的一对一化学配比抑制重组P-450DM的活性。同样，在重组P-450DM中加入等摩尔量的克霉唑、咪康唑或氟康唑时，酶活性也会受到完全抑制。这些结果与P-450DM在破碎细胞制剂中的抑制作用相关，证实了所有五种唑类药物都是白色念珠菌麦角甾醇生物合成的有效抑制剂。
The interaction of azole antifungal antibiotics with purified Candida albicans cytochrome P-450-dependent 14.alpha.-sterol, demethylase (P-450DM) was measured spectrophotometrically and by inhibition of enzyme activity. Ketoconazole and ICI 153066 (a triazole derivative) formed low-spin complexes with the ferric cytochrome and induced type II difference spectra. These spectra are indicative of an interaction between the azole moiety and the sixth co-ordination position of P-450DM haem. Both azoles inhibited the binding of CO to the sodium dithionite-reduced ferrous cytochrome, and inhibited reconstituted P-450DM activity by binding to the cytochrome with a one-to-one stoichiometry. Similarly, total inhibition of enzyme activity occurred when equimolar amounts of clotrimazole, miconazole or fluconazole were added to reconstituted P-450DM. These results correlated with the inhibition of P-450DM in broken cell preparations, confirming that all five azoles are potent inhibitors of ergosterol biosynthesis in C. albicans.