Developing Metallo-Beta-Lactamase Inhibitors

 描述(由申请人提供)：？内酰胺类药物是治疗细菌感染的重要药物。然而，细菌金属内酰胺酶(MBL)的出现使临床上几乎所有的药物都产生了耐药性(单巴拉西林除外)。可以说，出现的最令人担忧的MBL是新的Dehli金属内酰胺酶-1(NDM-1)，它可以降解所有几代已经测试的双环内酰胺类药物，包括青霉烯类、头孢类和碳青霉烯类。NDM-1已经在许多不同的肠杆菌科中被发现，并且是社区获得性的(不仅仅是医院内的)。该基因编码在能够水平转移的质粒中，该质粒也对大环内酯类、氨基糖苷类、利福平、磺胺甲恶唑和单环菌素产生抗药性。因此，MBLS，特别是NDM-1，代表着一个重大的新出现的全球健康威胁。尽管它很重要，但针对NDM-1或任何其他MBL的药物尚不为人所知。在撰写本文时，只有11种相对较弱的NDM-1抑制剂报道，其他与临床相关的MBLs的抑制剂在有效性和化学多样性方面有限。抑制剂的开发一直很困难，部分原因是这些酶具有灵活的活性部位以及相关的挑战 以金属酶为靶标。该提案将通过使用创新的 基于片段的药物发现与高通量筛选方法、抑制剂结合的详细表征、生物无机光谱、动力学、X射线结晶学和微生物功效分析相互补充。我们将对MBL抑制剂的两个保守特征进行深入的研究和优化：金属结合基团和与蛋白质柔性环相互作用的取代基。目的1利用具有特权的螯合片段文库鉴定对NDM-1和其他临床相关的B1内酰胺酶有抑制作用的部分。目的2利用多样性筛选来确定和优化结构上不同的抑制剂，以阐明灵活的NDM-1结合位点如何适应不同的配体。AIM 3使用一系列结构和光谱技术来表征、重新设计并最终优化这些抑制剂及其与NDM-1的相互作用。一支经验丰富的团队将有机合成、抑制剂筛选、药物化学、酶学、光谱学、结构生物学和微生物学方面的专业知识带入HITS，使其成为具有已知作用机制和微生物功效的有效NDM-1抑制剂。这项工作将为验证新的、有效的、结构多样的和具有生物用途的NDM-1抑制剂做出重要贡献。拟议的工作是创新的，因为应用了独特的螯合剂-片段发现方法，与许多B1内酰胺酶相关的广泛的抑制剂-靶标表征，以及多学科团队致力于开发急需的一流抑制剂，作为治疗设计的工具和先导化合物，以对抗NDM-1的全球威胁。

 DESCRIPTION (provided by applicant): ß-Lactams are drugs of vital importance for treatment of bacterial infections. However, the emergence of bacterial metallo-ß-lactamase (MBL) enzymes has enabled resistance to almost all clinically used drugs in this class (excepting the monobactams). Arguably, the most worrisome MBL to emerge is New Dehli Metallo-ß- lactamase-1 (NDM-1), which can hydrolyze all generations of bicyclic ß-lactams that have been tested, including penems, cephems, and carbapenems. NDM-1 has been identified in a number of different Enterobacteriaceae, and is community-acquired (not just nosocomial). The gene is encoded in plasmids capable of horizontal transfer that also confer resistance to macrolides, aminoglycosides, rifampicin, sulfamethoxazole, and monobactams. Therefore MBLs, and NDM-1 in particular, represent a significant emerging worldwide health threat. Despite its importance, drugs that target NDM-1, or any other MBL, are not known. At the time of writing, there are only ~11, relatively weak inhibitors reported for NDM-1, and inhibitors of the other most clinically-relevant MBLs are limited in efficacy and chemical diversity. Inhibitor development has been difficult, in part, due to the flexible active sites of these enzymes and the challenges associated with targeting metalloenzymes. This proposal will directly address this deficit by using innovative fragment-based drug discovery complimented with high-throughput screening approaches, detailed characterization of inhibitor binding, bioinorganic spectroscopy, kinetics, X-ray crystallography, and assays of microbial efficacy. We will conduct a deep investigation and optimization of two conserved features of MBL inhibitors: metal-binding groups and substituents that interact with the flexible loops of the protein. Aim 1 uses privileged chelator- fragment libraries to identify moieties effective for inhibition of NDM-1 and other clinically-relevant B1 lactamases. Aim 2 uses diversity screening to identify and optimize structurally divergent inhibitors to elucidate how the flexible NDM-1 binding sites accommodate different ligands. Aim 3 uses a battery of structural and spectroscopic techniques to characterize, re-design, and ultimately optimize these inhibitors and their interactions with NDM-1. An experienced team brings proficiency in organic synthesis, inhibitor screening, medicinal chemistry, enzymology, spectroscopy, structural biology, and microbiology to advance hits into potent NDM-1 inhibitors with known mechanisms of action and microbial efficacy. This work will make critical contributions to validating novel, potent, structurally-diverse, and biologically-useful NDM-1 inhibitors. The proposed work is innovative due to the application of a unique chelator-fragment discovery approach, the extensive inhibitor-target characterization relevant to many B1 lactamases, and the multidisciplinary team committed to developing much needed first-in-class inhibitors as tools and lead compounds for therapeutic design to counter the global threat of NDM-1.