H2S PRODUCTION AND VIRULENCE OF TREPONEMA DENTICOLA

牙螺旋体的 H2S 产生和毒力

• 批准号: 6380006
• 负责人: LIANRUI CHU
• 金额: $ 12.28万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2003-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6380006
• 关键词: Escherichia coli; SDS polyacrylamide gel electrophoresis; Treponema infection; aminoacid metabolism; bacterial genetics; bacterial proteins; cysteine; enzyme activity; enzyme linked immunosorbent assay; enzyme structure; enzyme substrate; glutathione; human tissue; hydrogen sulfide; inflammation; mutant; oral bacteria; periodontitis; periodontium; protein degradation; protein purification; pyruvates; tissue /cell culture; virulence; western blottings

DESCRIPTION (Adapted from the Investigator's Abstract): A characteristic feature of periodontitis is the existence of a variety of volatile sulfur compounds produced at sites of destructive disease. Hydrogen sulfide (H2S) is a major component of this family, which is a primary factor in halitosis related to periodontitis, and importantly, can affect host molecules and cells. Previous studies have identified a limited repertoire of oral microorganisms that can produce and survive in microenvironments with large amounts of H2S; however, the metabolic enzymes involved in the production of H2S are poorly understood. Substantial literature has identified T. denticola as one of the few oral bacteria with the capacity to produce and grow in high levels of H2S. The Principal Investigator has previously isolated and characterized an enzyme, cystalysin. This enzyme is unique to T. denticola and has a substrate specificity for L-cysteine, yielding pyruvate, NH3, and importantly, H2S. This proposal develops the general hypothesis that H2S is a significant effector of host responses in the local microenvironment of the periodontal disease site and, furthermore, that H2S-forming enzymes should be considered virulence determinants for T. denticola. Three specific aims are developed using biochemical, molecular genetic, and cell biologic studies to address this hypothesis: Specific Aim 1: To construct isogenic mutants altered in cystalysin-directed H2S producing capacity; Specific Aim 2: To biochemically characterize the enzyme pathway(s) involved in H2S production from glutathione; and, Specific Aim 3: To determine the effects of an H2S environment created by T. denticola on host inflammatory/immune functions. T. denticola has been identified as an important member of a specific consortia of microorganisms considered as etiologic in the development and progression of destruction of the periodontium. This proposal is designed to provide critical information related to the production of H2S by T. denticola, and for the first time to delineate the potential functions of H2S, which could deleteriously affect the homeostasis, maintained by molecules and cells in the periodontium. The outcomes would also be expected to provide an impetus to further target the enzymatic pathways contributing to H2S production as an innovative intervention strategy.

描述（改编自研究者摘要）：一个特征 牙周炎的一个特点是存在多种挥发性硫 在破坏性疾病部位产生的化合物。硫化氢（H2S）是一种 这个家族的主要组成部分，这是口臭相关的主要因素 牙周炎，重要的是，可以影响宿主分子和细胞。 以前的研究已经确定了有限的口腔微生物库 可以在含有大量H2S的微环境中产生和生存; 然而，参与H2S生产的代谢酶很少 明白大量的文献已经确定了T.齿垢作为一种 很少有口腔细菌能够在高水平的H2S中产生和生长。 主要研究者先前分离并表征了一种酶， 溶囊素这种酶是T.并具有基质 对L-半胱氨酸的特异性，产生丙酮酸、NH3和重要的H2S。这 该提案提出了一个一般假设，即H2S是一个显着的效应， 牙周病局部微环境中的宿主反应 此外，H2S形成酶应被视为毒性 决定因素T。齿垢制定了三个具体目标， 生物化学、分子遗传学和细胞生物学研究来解决这个问题 假设：具体目标1：构建改变的同基因突变体， 胱分解酶导向的H2S产生能力;具体目标2：生物化学 表征参与谷胱甘肽产生H2S的酶途径; 具体目标3：确定由下列因素造成的H2S环境的影响 T.齿垢对宿主炎症/免疫功能的影响。T.齿垢一直是 被鉴定为特定微生物聚生体的重要成员 被认为是在发展和发展的破坏病因， 牙周组织本提案旨在提供关键信息 与T.第一次，我就被他给弄死了。” 描述了H2S的潜在功能，这可能会对 内环境稳定，由牙周组织中的分子和细胞维持。的 预计成果还将推动进一步针对 促进H2S产生的酶途径作为一种创新干预措施 战略