Scaffolds for Synthesis of Probes Directed Against Class II HMG-CoA Reductases

描述（由申请人提供）：最近有研究表明，许多常见的人类病原体，包括粪肠球菌、肺炎链球菌和金黄色葡萄球菌，都依赖于甲羟戊酸途径中的酶来生物合成IPP，包括中心途径酶HMG-CoA还原酶。这提出了一种可能性，即HMG-CoA还原酶的靶向抑制剂将是这些病原体的抗菌特异性，具有独特的攻击点，这类抑制剂将不受针对更常见的细胞壁拮抗剂开发的耐药机制的影响。这种选择性将使甲羟戊酸途径抑制剂在烧伤病房或重症监护病房特别有吸引力，在这些地方，正常菌群的灭菌使酵母菌过度生长或耐药菌定植成为广谱抗生素使用的常见和严重并发症。本提案的目的是鉴定一组选择性抑制致病菌II类HMG-CoA还原酶（HMGR）活性的分子探针。本提案寻求获得分子文库筛选中心网络（MLSCN）提供的HTS资源，在那里可以使用HTS-ready检测来探索人类和致病菌hmgr结构活性关系的差异。一项使用高通量分光光度法的初步研究表明，该方法非常稳健，并鉴定出7种具有显著抑制作用的化合物（命中率为0.18%），因此可以转化为指定的筛选中心。建议在合作实验室进行二级分析，以确认效力并进一步了解抑制的分子基础，包括更详细的酶学分析所选化合物的抑制作用，细菌毒性评估以及这些化合物与细菌hmgr复合物的详细结构研究。最近有研究表明，许多常见的人类病原体，包括粪肠球菌、肺炎链球菌和金黄色葡萄球菌，都依赖于甲羟戊酸途径中的酶来生物合成IPP，包括中心途径酶HMG-CoA还原酶。这提出了一种可能性，即HMG-CoA还原酶的靶向抑制剂将是这些病原体的抗菌特异性，具有独特的攻击点，这类抑制剂将不受针对更常见的细胞壁拮抗剂开发的耐药机制的影响。这种选择性将使甲羟戊酸途径抑制剂在烧伤病房或重症监护病房特别有吸引力，在这些地方，正常菌群的灭菌使酵母菌过度生长或耐药菌定植成为广谱抗生素使用的常见和严重并发症。

DESCRIPTION (provided by applicant): It has recently been shown that a number of common human pathogens, including Enterococcus faecalis, Streptococcus pneumoniae and Staphylococcus aureus are dependent on enzymes in the mevalonate pathway for biosynthesis of IPP, including the central pathway enzyme HMG-CoA reductase. This raises the possibility that a targeted inhibitor of HMG-CoA reductase would be an anti-bacterial specific for these pathogens, with a unique point of attack that would leave this class of inhibitors unaffected by the resistance mechanisms that have developed against the more common cell-wall antagonists. This selective property would make mevalonate pathway inhibitors particularly attractive in burn unit or intensive care settings where sterilization of the normal bacterial flora make yeast over growth or colonization by resistant bacteria a common and severe complication of broad-spectrum antibiotic use. The goal of this proposal is to identify a set of molecular probes that selectively inhibit the activity of the Class II HMG-CoA reductase (HMGR) of pathogenic bacteria. This proposal seeks access to HTS resources provided by the Molecular Libraries Screening Center Network (MLSCN) where an HTS-ready assay can be employed to explore the differences in the structure activity relationships of the human and pathogenic bacterial HMGRs. A preliminary study using a spectrophotometric assay in high throughput format has demonstrated this assay is exceptionally robust, and identified seven compounds (0.18% hit rate) with significant inhibitory effects, and therefore is ready to be translated to a designated screening center. Secondary assays to be performed in the collaborating laboratories are proposed to confirm the potency and to further understand the molecular basis of the inhibition, including more detailed enzymology of the inhibitory effects selected compounds, bacterial toxicity assessments and detailed structural studies of these compounds in complexes with bacterial HMGRs. It has recently been shown that a number of common human pathogens, including Enterococcus faecalis, Streptococcus pneumoniae and Staphylococcus aureus are dependent on enzymes in the mevalonate pathway for biosynthesis of IPP, including the central pathway enzyme HMG-CoA reductase. This raises the possibility that a targeted inhibitor of HMG-CoA reductase would be an anti-bacterial specific for these pathogens, with a unique point of attack that would leave this class of inhibitors unaffected by the resistance mechanisms that have developed against the more common cell-wall antagonists. This selective property would make mevalonate pathway inhibitors particularly attractive in burn unit or intensive care settings where sterilization of the normal bacterial flora make yeast over growth or colonization by resistant bacteria a common and severe complication of broad-spectrum antibiotic use.