Dynamics and Interactions of Cytochrome P450 19A1

细胞色素P450（CYP）负责在处置中的一系列令人眼花缭乱的转换， 异生物质和激素的生物合成。超过70%的药物是由CYP代谢的;因此， 在药物开发中将资源用于鉴定底物和抑制剂以避免以后的损耗， 或引入临床后的不良药物相互作用。其中，参与类固醇的CYP 激素生物合成是内分泌失调药物治疗的关键靶点之一， 癌的CYP的催化选择性范围和底物转化的广度是巨大的; 然而，用于实现这种灵活性的蛋白质动力学、配体结合和催化的相互作用仍然存在 不太了解。在这个空白中，没有人知道这些是如何受到他们的生理影响的。 上下文我们采用了人芳香酶（CYP 19 A1），负责雌激素的生物合成， 雄激素作为解决这些长期存在的重要问题的模型。系统发育分析支持 CYP 19 A1是最原始的人类CYP之一，它在功能上代表了那些 催化连续转化的类固醇生成酶。CYP 19 A1的翻译相关性不能 由于它在维持许多组织中起着重要作用，并且已经证明了巨大的 作为妇科疾病、癌症和不孕症的药物治疗靶点的价值。具体有三个 为了验证我们的假设，我们将：1）绘制19 A1配体进入、产物流出的途径，并描绘19 A1配体进入、产物流出的途径。 选择性的结构基础。工作假设是：i）底物，中间产物， 和抑制剂产生独特的平衡动力学和ii）选择性是由瞬时结合赋予的 状态作为配体通过不同的通道进入和离开酶。2)描述膜的影响 19 A1中催化、配体结合动力学和全局动力学的复杂性。工作假设是i） 选择性由涉及多个蛋白质状态和构象转变的动力学主导，ii）催化 和抑制性19 A1复合物显示不同的动力学，和iii）蛋白质动力学和结合动力学 受到膜特性的影响。3)通过以下方式确定19 A1-ND在可变环境中的架构： 小角度X射线和中子散射。工作假设是，插入深度和方向的 19 A1的分子量取决于双层的表面和本体性质。这些目标在技术上是- 独立的，但融合的方法，在组合中高度协同，不仅允许 对CYP 19 A1的新见解，也揭示了将改变我们对CYP 19 A1功能理解的范式。

The cytochromes P450 (CYPs) are responsible for a dazzling array of transformations in the disposition of xenobiotics and biosyntheses of hormones. Over 70% of drugs are metabolized by CYPs; hence tremendous resources are devoted to identification of substrates and inhibitors in drug development to avoid later attrition, or adverse drug interactions following introduction into the clinic. Among these, CYPs involved in steroid hormone biosyntheses are among the key targets for the pharmacotherapy of endocrine disorders and cancers. The range of catalytic selectivity and the breadth of substrates transformed by CYPs are immense; however the interplay of protein dynamics, ligand binding, and catalysis used to achieve this flexibility remains poorly understood. Within this void, nothing is known about how these are impacted by their physiological context. We have adopted human aromatase (CYP19A1), responsible for estrogen biosynthesis from androgens, as a model to address these longstanding and important questions. Phylogenetic analysis supports that CYP19A1 is among the most primordial human CYPs and it is functionally representative of those steroidogenic enzymes catalyzing sequential transformations. The translational relevance of CYP19A1 cannot be underestimated since it has vital role in maintaining numerous tissues and has demonstrated immense value as a pharmacotherapy target for gynecological disorders, cancers and infertility. There are three Specific Aims to test our hypotheses, we will: 1) Map pathways for 19A1 ligand entry, product egress, and delineate the structural underpinnings of selectivity. The working hypotheses are that i) substrates, intermediate products, and inhibitors give rise to unique equilibrium dynamics and ii) that selectivity is conferred by transient bound states as ligands enter and exit the enzyme through distinct channels. 2) Delineate the impact of membrane complexity on catalysis, ligand binding kinetics and global dynamics in 19A1. The working hypotheses are i) Selectivity is dominated by kinetics involving multiple protein states and conformational transitions, ii) catalytic and inhibitory 19A1 complexes display distinct dynamics, and iii) both protein dynamics and binding kinetics are impacted by membrane properties. 3) Determine the architecture of 19A1-NDs in variable environments by small-angle x-ray and neutron scattering. The working hypothesis is that the insertion depth and orientation of 19A1 are determined by the surface and bulk properties of the bilayer. These Aims are technically- independent, but convergent approaches that are highly synergistic in combination, and will not only allow novel insight into CYP19A1, but also unveil paradigms that will transform our understanding of CYP function.