Mechanism of Slow Onset Enzyme Inhibition and Translation to Time-Dependent Drug Activity

许多候选药物由于缺乏疗效或安全性不足而在临床试验中失败。我们 推测我们在预测体内药物疗效方面的低成功率源于对 在恒定药物浓度下进行的药物活性的体外评估（在 平衡条件），而实际上药物浓度在人体内不是恒定的。我们 因此提出药物-靶点复合物形成和分解的动力学是一个关键因素 在调节药物作用方面。在这个建议中，我们将阐明决定生物学特性的分子因素。 药物-靶标停留时间对体内药物活性影响。这些研究将集中在抑制剂 UDP-3-O-（R-3-hydroxymyristoyl）-N-acetylglucosamine deacetylase （LpxC）、乙酰辅酶A羧化酶（ACC）和亮氨酰-tRNA合成酶（LeuRS）。我们将量化 细胞内事件如靶（再）合成、靶降解和靶 药物靶点滞留时间与抗菌活性之间的相关性 确定为药物浓度的函数。这包括延长抗菌 从系统中去除药物后的活性（抗生素后效应）。我们将开发 时间依赖性酶抑制的结构-动力学关系， 结构和计算生物学结合酶动力学和合成抑制剂 延长目标攻击时间一个数学模型将被用来连接药物-靶点动力学 和药物药代动力学，预测全细胞和动物中的抗菌活性 感染的模型。提高从体外参数预测体内药物作用的能力， 对发现新的治疗药物有着巨大的影响。

Many drug candidates fail in clinical trials due to lack of efficacy or insufficient safety. We speculate that our poor success rate at predicting in vivo drug efficacy stems from a reliance on in vitro assessments of drug activity that are performed at constant drug concentration (under equilibrium conditions), when in fact drug concentration is not constant in the human body. We thus propose that the kinetics of drug-target complex formation and breakdown is a critical factor in modulating drug action. In this proposal we will elucidate the molecular factors that dictate the impact of drug-target residence time on in vivo drug activity. These studies will focus on inhibitors of three antibacterial targets: UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase (LpxC), acetyl-CoA carboxylase (ACC) and leucyl-tRNA synthetase (LeuRS). We will quantify the role that intracellular events such as target (re)synthesis, target degradation and target vulnerability have on the correlation between drug-target residence time and antibacterial activity determined as a function of drug concentration. This includes the prolongation of antibacterial activity following removal of drug from the system (the post-antibiotic effect). We will develop structure-kinetics relationships for time-dependent enzyme inhibition using a combination of structural and computational biology coupled with enzyme kinetics and synthesize inhibitors with extended target engagement. A mathematical model will be used that links drug-target kinetics and drug pharmacokinetics with predictions of antibacterial activity in whole cells and animal models of infection. Improved ability to predict in vivo drug action from in vitro parameters will have a dramatic impact on the discovery of new therapeutic agents.