ABSTRACT
Cryptococcosis is a life-threatening disease often associated with HIV infection. Three
Cryptococcus
species CYP51 enzymes were purified and catalyzed the 14α-demethylation of lanosterol, eburicol, and obtusifoliol. The investigational agent VT-1129 bound tightly to all three CYP51 proteins (dissociation constant [
K
d
] range, 14 to 25 nM) with affinities similar to those of fluconazole, voriconazole, itraconazole, clotrimazole, and ketoconazole (
K
d
range, 4 to 52 nM), whereas VT-1129 bound weakly to human CYP51 (
K
d
, 4.53 μM). VT-1129 was as effective as conventional triazole antifungal drugs at inhibiting cryptococcal CYP51 activity (50% inhibitory concentration [IC
50
] range, 0.14 to 0.20 μM), while it only weakly inhibited human CYP51 activity (IC
50
, ∼600 μM). Furthermore, VT-1129 weakly inhibited human CYP2C9, CYP2C19, and CYP3A4, suggesting a low drug-drug interaction potential. Finally, the cellular mode of action for VT-1129 was confirmed to be CYP51 inhibition, resulting in the depletion of ergosterol and ergosta-7-enol and the accumulation of eburicol, obtusifolione, and lanosterol/obtusifoliol in the cell membranes.
摘要
隐球菌病是一种威胁生命的疾病,通常与艾滋病毒感染有关。三种
隐球菌
种 CYP51 酶被纯化并催化了羊毛甾醇、桉叶油醇和欧曲唑醇的 14α 去甲基化。研究药物 VT-1129 与所有三种 CYP51 蛋白都紧密结合(解离常数[...])。
K
d
范围为 14 至 25 nM),其亲和力与氟康唑、伏立康唑、伊曲康唑、克霉唑和酮康唑相似 (
K
d
范围为 4 至 52 nM),而 VT-1129 与人类 CYP51 的结合力较弱 (
K
d
为 4.53 μM)。在抑制隐球菌 CYP51 活性方面,VT-1129 与传统的三唑类抗真菌药物一样有效(50% 抑制浓度 [IC
50
范围为 0.14 至 0.20 μM),而它对人类 CYP51 活性的抑制作用很弱(IC
50
600 μM)。此外,VT-1129 对人类 CYP2C9、CYP2C19 和 CYP3A4 也有微弱的抑制作用,表明其药物相互作用潜力较低。最后,VT-1129 的细胞作用模式被证实为抑制 CYP51,导致麦角甾醇和麦角甾-7-烯醇耗竭,勃立醇、obtusifolione 和羊毛甾醇/obtusifoliol 在细胞膜中积累。