Modern Drug Resistance: Elucidation of Beta-Lactamase Mechanisms of Action

描述(由申请人提供)： 医院中新出现的耐药细菌威胁是临床医生目前面临的最紧迫的流行病之一。最近对心脏ICU的一项研究发现，75%的金黄色葡萄球菌和95%的凝固酶阴性葡萄球菌被鉴定为耐甲氧西林。β-内酰胺类抗生素(例如青霉素、头孢菌素)通过破坏细菌转肽酶的活性来发挥作用，转肽酶是产生细菌细胞壁的主要原因。为了对抗这些药物，细菌使用了β-内酰胺酶，这是它们对抗生素最常见的防御措施。为了应对这个问题，在市面上可以买到的抗生素中加入了抑制剂，这些抗生素结合并抑制了β-内酰胺酶的活性。这项工作的长期目标是帮助开发和了解以β-内酰胺为基础的抗生素和抑制剂。这可以通过更好地了解控制耐药性的潜在机制并提出利用这些信息的方法来实现。我假设，新的计算方法的开发和应用可以评估当前药物开发战略的有效性。具体地说，新的抗生素是否应该以更好地结合多肽酶为目标，还是应该采用替代策略？我们最初的目标是开发和验证计算蛋白质辅助化学反应自由能的新方法。完成后，我们将使用这些方法来确定未来的基于β-内酰胺的抗生素是否应该针对天然细菌肽酶的更大结合亲和力，或者是否更有利于设计优先稳定基于蛋白质的化学反应的药物。我们的最终目标将包括计算天然和突变的β-内酰胺酶状态的自由能，并研究这些蛋白质在抑制抑制剂活性的同时维持分解抗生素的能力的机制。这些目标的完成将导致对耐药性机制的更好描述，并将使研究人员能够在创造新的抗生素和抑制剂时利用这些信息。这笔赠款的资金将通过额外的培训(例如，课程、咨询、演示、赠款撰写、研究)来支持我的职业发展。此外，我计划利用在国立卫生研究院的教学机会，这将独特地促进我过渡到一个独立的助理教授职位的愿望。(摘要结束)

DESCRIPTION (provided by applicant): The emerging threat of drug resistant bacteria in hospitals is one of the most pressing pandemics clinicians are currently facing. A recent study of cardiac ICUs found that 75% of Staphylococcus aureus and 95% of coagulase-negative staphylococci were identified as methicillin resistant. The beta-lactam class of antibiotics (e.g. penicillins, cephalosporins) work by disrupting the activity of bacterial transpeptidases which are largely responsible for creating bacterial cell walls. To combat these drugs bacteria employ beta-lactamases, which are their most common defense against antibiotics. In response to this problem inhibitors are added to commercially available antibiotics which bind and depress beta-lactamase activity. The long term goals of this work are to assist in the development and understanding of beta-lactam based antibiotics and inhibitors. This can be accomplished by better understanding the underlying mechanisms that govern drug resistance and proposing ways to exploit this information. I hypothesize that the development and application of novel computational methods can evaluate the effectiveness of current drug development strategies. Specifically, should new antibiotics be targeted toward better binding in peptidases or should an alternative strategy be employed? Our initial aim is to develop and validate novel methods for calculating the free energies of protein assisted chemical reactions. Upon completion we will employ these methods to determine whether future beta-lactam based antibiotics should be targeted toward greater binding affinity in native bacterial peptidases or whether it is more advantageous to design drugs that preferentially stabilize protein based chemical reactions. Our final aim will involve computing the free energy of native and mutant beta-lactamase states and examining mechanisms by which these proteins sustain the ability to break down antibiotics while repressing inhibitor activity. Completion of these aims will result in an improved description of drug resistance mechanisms and will allow researchers to exploit this information in the creation of new antibiotics and inhibitors. The funding from this grant will support the my career development via additional training (e.g. courses, advisement, presentations, grant writing, research). In addition, I plan to take advantage of the teaching opportunities at NIH which will give a unique boost to my desire to transition into an independent assistant professor position. (End of Abstract)