Sulfotransferase Specificity and the Development of Sulfation Resistant Compounds

磺基转移酶特异性和抗硫酸化化合物的开发

• 批准号: 8695910
• 负责人: Thomas S. Leyh
• 金额: $ 38.09万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8695910
• 关键词: Active Sites; Affinity; Allosteric Regulation; Amines; Apomorphine; Area; Aspirin; Basic Science; Behavior; Binding; Binding Sites; Biological Assay; Biology; Cells; Complex; Computer Simulation; Data; Development; Disease; Dopamine; Dopamine Agonists; Enzymes; Epigallocatechin Gallate; Equilibrium; Estrogen Receptors; Estrogens; Ethinyl Estradiol; FDA approved; Family; Foundations; Goals; Hand; Heart; Hepatocyte; Human; Hydroxyl Radical; In Vitro; Isoenzymes; Lead; Ligand Binding; Ligands; Literature; Liver; Mammalian Cell; Metabolism; Modeling; Modification; Molecular; Nucleotides; Nutrient; Optruma; Oral Contraceptives; Parkinson Disease; Perception; Pharmaceutical Preparations; Pharmacologic Substance; Phenylalanine; Positioning Attribute; Publishing; Raloxifene; Reagent; Receptor Activation; Regulation; Research Design; Resistance; Resolution; Roentgen Rays; Role; Selective Estrogen Receptor Modulators; Series; Site; Specificity; Staging; Steroids; Structure; Substrate Specificity; Sulfur Metabolism Pathway; System; Tea; Testing; Therapeutic; Xenobiotics; base; celecoxib; design; drug efficacy; falls; improved; in vivo; inhibitor/antagonist; insight; member; mutant; novel; novel strategies; prevent; public health relevance; receptor; receptor binding; salicylate; small molecule; sulfation; sulfotransferase

DESCRIPTION (provided by applicant): The objective of this proposal is to obtain a deep and fundamental understanding of the molecular behavior of the human cytosolic sulfotransferases. This 13-member enzyme family regulates the receptor interactions of hundreds of small molecules by transferring the sulfuryl-group (-SO3) from a nucleotide donor (PAPS, 3'-phosphoadenosine 5'-phosphosulfate) to the hydroxyl- or amine-moieties of small-molecule acceptors. Understanding the molecular interactions between SULTs and their substrates and allosteric modulators will substantially deepen our understanding of the roles of these enzymes in biology and provide a means of controlling SULT activity in-vivo. Aim I. We have discovered that SULT1A1 uses positive synergy to enhance the catalytic efficiencies of select substrates 103-104-fold. This is the first example of positive synergy in the SULT field. The molecular basis of these stunning catalytic enhancements will be determined, and the substrate features that elicit positive synergy will be identified with the goal of understanding how SULT-substrate reactivity is controlled. Aim II focuses on an important and virtually unexplored area in sulfur metabolism - the allosteric regulation of SULT function. The literature describes a small number of important drugs and nutrients (aspirin, Celebrex (r), Ponstel (r) and epigallocatechin gallate - which comprises ~ 12% of the mass of dry tea leaves) that regulate SULTs by binding at sites separate from those of substrates. Binding is tight, isozyme specific and physiologically relevant. Certain compounds inhibit while others change the specificity and activate turnover of the enzyme. We will determine the first allostere-bound SULT structures - the crystals needed to do this are in-hand. Seeing these ligand-bound allosteric pockets at atomic resolution will change our perceptions of SULT metabolism and provide novel opportunities to control SULT activity. Aim III. Hundreds of FDA-approved drugs are inactivated by sulfation. Preventing this modification is expected to increase the concentration and half-lives of the active forms of these compounds in-vivo. Classical inhibition strategies are detrimental because they prevent essential SULT functions. Consequently, no means of achieving this end is described in the literature. Our recent insights into the molecular basis of SULT-substrate selectivity lay the foundations for a novel strategy to prevent sulfation without inhibiting SULTs or altering a compound's receptor-binding affinity. We will develop this strategy and demonstrate its therapeutic potential. Sidechains that prevent sulfation will be identified and inserted into two FDA-approved drugs whose bioactivities are potently suppressed by sulfation: apomorphine, used to treat late-stage Parkinson Disease, and ethinyl estradiol, the active estrogen in most oral contraceptives. The receptor affinities of these new compounds will be tested in mammalian cells and their metabolism will be evaluated using primary human hepatocytes.

描述（由申请人提供）：该提案的目的是获得对人类胞质磺基转移酶的分子行为的深入和基本的了解。这个由 13 名成员组成的酶家族通过将硫酰基 (-SO3) 从核苷酸供体（PAPS、3'-磷酸腺苷 5'-磷酸硫酸盐）转移到小分子受体的羟基或胺部分来调节数百个小分子的受体相互作用。了解 SULT 及其底物和变构调节剂之间的分子相互作用将大大加深我们对这些酶在生物学中的作用的理解，并提供控制体内 SULT 活性的方法。目标 I。我们发现 SULT1A1 利用正协同作用将选定底物的催化效率提高 103-104 倍。这是SULT领域积极协同的第一个例子。这些令人惊叹的催化增强的分子基础将被确定，并且将确定引发积极协同作用的底物特征，目的是了解如何控制 SULT 底物反应性。目标 II 关注硫代谢中一个重要且几乎未被探索的领域 - SULT 功能的变构调节。文献描述了少数重要的药物和营养素（阿司匹林、Celebrex (r)、Ponstel (r) 和表没食子儿茶素没食子酸酯 - 约占干茶叶质量的 12%），通过与底物分开的位点结合来调节 SULT。结合紧密、同工酶特异性且具有生理相关性。某些化合物会抑制酶，而另一些化合物会改变酶的特异性并激活酶的更新。我们将确定第一个与别构结合的 SULT 结构 - 所需的晶体已在手。在原子分辨率下观察这些配体结合的变构袋将改变我们对 SULT 代谢的看法，并为控制 SULT 活性提供新的机会。目标三。数百种经 FDA 批准的药物可通过硫酸盐化而失活。防止这种修饰预计会增加这些化合物活性形式的体内浓度和半衰期。经典的抑制策略是有害的，因为它们会阻止基本的 SULT 功能。因此，文献中没有描述实现该目的的方法。我们最近对 SULT 底物选择性的分子基础的见解为防止硫酸化而不抑制 SULT 或改变化合物的受体结合亲和力的新策略奠定了基础。我们将开发这一策略并展示其治疗潜力。防止硫酸化的侧链将被鉴定并插入两种 FDA 批准的药物中，这两种药物的生物活性会被硫酸化有效抑制：阿扑吗啡（用于治疗晚期帕金森病）和乙炔雌二醇（大多数口服避孕药中的活性雌激素）。这些新化合物的受体亲和力将在哺乳动物细胞中进行测试，并使用原代人肝细胞评估它们的代谢。