H2S PRODUCTION AND VIRULENCE OF TREPONEMA DENTICOLA

牙螺旋体的 H2S 产生和毒力

• 批准号: 6516624
• 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 2004-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6516624
• 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（改编自调查员的摘要）：一个特征 牙周炎的特征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 该家族的主要组成部分，这是与降落量相关的主要因素 牙周炎，重要的是会影响宿主分子和细胞。 先前的研究已经确定了有限的口服微生物曲目 可以在具有大量H2的微环境中产生和生存； 但是，与H2的生产有关的代谢酶很差 理解。大量文献已经确定牙霉菌是其中之一 很少有口服细菌具有高水平的H2s的能力。 主要研究者先前已经分离并表征了一种酶， 胱胱氨酸蛋白酶。该酶是T. denticola独有的，具有底物 L-半胱氨酸的特异性，产生丙酮酸NH3，重要的是H2S。这 提案提出了一个普遍的假设，即H2S是 牙周疾病部位的局部微环境中的宿主反应 此外，应将H2S形成酶视为毒力 T.牙本质的决定因素。使用三个特定目标使用 生化，分子遗传和细胞生物学研究以解决这一问题 假设：特定目的1：构建在 囊肿素定向的H2S产能；特定目标2：生化 表征谷胱甘肽H2S生产中涉及的酶途径； 并且，特定目的3：确定由H2S环境创造的影响 T. denticola在宿主炎症/免疫功能上。 T. Denticola一直 被确定为微生物特定财团的重要成员 被认为是毁灭性发展和发展的病因 牙周。该建议旨在提供关键信息 与T. denticola的H2S生产有关，这是第一次 描述H2S的潜在功能，这可能会影响 稳态，由牙周分子和细胞维持。这 结果也有望提供推动力，以进一步定位 酶促途径有助于H2S生产作为创新干预措施 战略。