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。最近一项针对心脏ICU的研究发现，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，而细菌转肽酶在很大程度上负责产生细菌细胞壁。为了对抗这些药物，细菌使用β-内酰胺酶，这是它们对抗生素最常见的防御。为了解决这个问题，将抑制剂添加到市售抗生素中，其结合并抑制β-内酰胺酶活性。这项工作的长期目标是帮助开发和理解基于β-内酰胺的抗生素和抑制剂。这可以通过更好地理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策略的有效性。具体来说，新的抗生素是否应该以更好地结合肽酶为目标，或者是否应该采用替代策略？我们的初步目标是开发和验证新的方法来计算蛋白质辅助化学反应的自由能。完成后，我们将采用这些方法来确定未来的β-内酰胺类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蛋白质化学反应的药物。我们的最终目标将包括计算天然和突变β-内酰胺酶状态的自由能，并研究这些蛋白质在抑制剂活性的同时维持分解抗生素的能力的机制。这些目标的实现将改善对耐药机制的描述，并使研究人员能够利用这些信息来创造新的抗生素和抑制剂。这笔赠款的资金将通过额外的培训（例如课程，培训，演讲，赠款写作，研究）来支持我的职业发展。此外，我计划利用在NIH的教学机会，这将给我的愿望过渡到一个独立的助理教授的位置一个独特的推动。(End摘要）

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)