STUDIES ON THE DEXTRANSUCRASE OF STREPTOCOCCUS SANGUIS

血链球菌葡聚糖蔗糖酶的研究

• 批准号: 3218904
• 负责人: ROBERT MAYER
• 金额: $ 9.32万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-01-01 至 1988-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3218904
• 关键词: Streptococcus sanguis; carbohydrate biosynthesis; chemical reaction; chromatography; dental caries; dental plaque; detergents; dextrans; enzyme structure; glycosyltransferase; oral bacteria; polymers; radiotracer; scintillation counter; tissue /cell culture

Dextransucrase catalyzes the formation of a glucan containing Alpha 1-6 and Alpha 1-3 bonds. The glucan, dextran, is a major component of dental plaque and is formed by the action of the enzyme on sucrose. Studies are proposed that will extend work that is currently in progress. Elements of the reaction pathway will be studied to evaluate the physiological importance of two alternate pathways of polymer formation. Similarly, the significance of the reversibility of these reactions will be assessed. The mechanism involved in the formation of the two bond types is to be studied along with the question of whether this is a regulated process. The active site of the enzyme is to be probed by use of chemical modifying agents. In addition, compounds that may serve as active-site directed inactivators will be synthesized and studied. The enzyme has been shown to have unique behavior with detergents. In the presence of SDS it is completely inactivated, and upon the addition of Triton X-100 it is completely reactivated. Studies are planned that will explore the molecular events associated with this behavior.

葡聚糖蔗糖酶催化含有α 1-6的葡聚糖的形成， α 1-3键。 葡聚糖，右旋糖酐，是牙科的主要成分， 菌斑，并通过酶对蔗糖的作用形成。 研究是 这将扩大目前正在进行的工作。 要素 将研究反应途径以评估生理学 聚合物形成的两种交替途径的重要性。 类似地， 将评估这些反应可逆性的显著性。 的 这两种键型的形成机理有待研究 沿着的问题是这是否是一个受监管的过程。 活性 通过使用化学修饰剂来探测酶的位点。 在 此外，可用作活性位点定向灭活剂的化合物 将进行合成和研究。 该酶已被证明对洗涤剂具有独特的行为。 在 SDS的存在下，它是完全失活的，并在添加 Triton X-100完全被激活。 研究计划将 探索与这种行为相关的分子事件。