Developing Metallo-Beta-Lactamase Inhibitors

 性状（由申请方提供）：β-内酰胺类药物是治疗细菌感染的重要药物。然而，细菌金属-β-内酰胺酶（MBL）的出现使得几乎所有临床使用的该类药物（除了单环内酰胺类）都具有耐药性。可以说，出现的最令人担忧的MBL是新德里金属β-内酰胺酶-1（NDM-1），它可以水解已测试的所有代双环β-内酰胺，包括青霉烯类、头孢烯类和碳青霉烯类. NDM-1已在许多不同的肠杆菌科中鉴定，并且是社区获得性的（不仅仅是医院获得性的）。该基因编码在能够水平转移的质粒中，也赋予对大环内酯类、氨基糖苷类、利福平、磺胺甲恶唑和单环内酰胺类的抗性。因此，MBL，特别是NDM-1，代表了一个重要的新兴全球健康威胁。尽管其重要性，靶向NDM-1或任何其他MBL的药物尚不清楚。在撰写本文时，仅报告了~11种相对较弱的NDM-1抑制剂，其他最具临床相关性的MBL抑制剂的疗效和化学多样性有限。抑制剂的开发一直很困难，部分原因是这些酶的活性位点灵活，以及相关的挑战 靶向金属酶。该提案将通过使用创新的方法来直接解决这一赤字问题。 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、生物无机光谱学、动力学、X射线晶体学和微生物功效测定相辅相成。我们将对MBL抑制剂的两个保守特征进行深入研究和优化：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使用特权螯合剂片段文库来鉴定有效抑制NDM-1和其他临床相关的B1内酰胺酶的部分。目的2利用多样性筛选来鉴定和优化结构不同的抑制剂，以阐明柔性NDM-1结合位点如何适应不同的配体。目标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。一个经验丰富的团队带来了熟练的有机合成，抑制剂筛选，药物化学，酶学，光谱学，结构生物学和微生物学，以推进打击到有效的NDM-1抑制剂与已知的作用机制和微生物功效。这项工作将为验证新的，有效的，结构多样的和生物学上有用的NDM-1抑制剂做出关键贡献。由于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，以应对NDM-1的全球威胁，因此拟议的工作是创新的。

 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.