Novel antibacterial target: an essential glycoprotease

描述(申请人提供)：多重耐药细菌病原体的出现，特别是耐甲氧西林和万古霉素中间耐药的金黄色葡萄球菌正在产生巨大的公共卫生问题。其中许多病原体能够造成严重甚至致命的感染，治疗选择有限。过去几十年来，发现新型抗生素的速度放缓，最近制药业抗菌药物的发现和开发也出现了下滑，这使我们更容易受到新出现的耐药性的影响。因此，迫切需要新的替代药物来治疗多重耐药病原体。最近获得的病原体的完整基因组序列使我们能够对细菌生长和感染所需的每个基因/操纵子进行系统和全面的评估。细菌在体外生长和在感染期间存活所必需的基因产物构成了一套初步的有效蛋白质靶标，可以进行优化和自动筛选。我们的长期目标是确定新的靶点，以提供有效的预防和/或治疗金黄色葡萄球菌感染的药物。具体的假设是，一个假定的糖蛋白(GCP)是一个新的抗菌靶点，参与细菌生存所需的途径。然而，GCP的生物学功能及其对生长和生存的重要性仍不清楚。阐明GCP的精确功能将为体外试验的发展奠定基础，而体外试验是药物发现必不可少的。因此，本研究的目的是确定GCP的生物学功能，确定GCP参与的途径，并开发一种潜在的检测方法。我们将追求以下三个具体目标来验证我们的中心假设：第一，我们将表征金黄色葡萄球菌所必需的糖蛋白水解酶。其次，我们将使用微阵列技术来识别葡萄球菌基因，这些基因的转录受到假定的糖蛋白水解酶功能条件失活的影响。第三，我们将利用蛋白质组学方法识别受GCP表达下调影响的蛋白质，并将这些数据与微阵列数据进行比较。

DESCRIPTION (provided by applicant): The emergence of multi-drug resistant bacterial pathogens, especially methicillin-resistant and vancomycin intermediate-resistant Staphylococcus aureus is generating an enormous public health concern. Many of these pathogens are capable of causing severe and even fatal infections with limited options for therapy. The slowdown in the discovery of novel classes of antibiotics in past several decades and the recent downturn in antibacterial discovery and development in the pharmaceutical industry is making us more vulnerable to emerging resistance. Therefore, there is an urgent need for new, alternative agents for treating multi-drug-resistant pathogens. The recent availability of the complete genome sequences for pathogens enables us to undertake a systematic and comprehensive evaluation of the requirement for each and every gene/operon for both bacterial growth and infection. The gene products essential for bacterial growth in vitro and survival during infection constitute an initial set of validated protein targets that can be optimized and automated screens. Our long-term goal is to identify novel targets for delivering efficacious preventive and/or therapeutic agents against S. aureus infections. The specific hypothesis is that a putative glycoprotease (Gcp) is a novel antibacterial target involved in the pathway required for bacterial survival. However, the biological function of Gcp and its importance for growth and survival remains unclear. Elucidation of the precise function of Gcp will lead to the basis for the development of an in vitro assay, which is indispensable for the drug discovery. Therefore, the objective of this proposal is to determine the biological function of Gcp, identify pathway that Gcp is involved in, and to develop a potential assay. We will pursue the following three specific aims to test our central hypothesis: First, we will characterize the essential putative glycoprotease of S. aureus. Second, we will employ microarray technology to identify staphylococcal genes, transcriptions of which are affected by conditional inactivation of putative glycoprotease function. Third, we will utilize proteomic approaches to identify proteins that are affected by down-regulation of gcp expression and compare this data with microarray data.