REGULATION OF SUGAR TRANSPORT AND METABOLISM IN LACTIC ACID AND ORAL BACTERIA

这个项目集中在一个基础科学研究项目上。 强调生理学、生物化学和遗传学基础 口腔中氨基酸和糖发酵途径的调控 细菌。这一基本知识对于识别 口腔溃疡的病因、治疗和预防的制定 疾病。在此期间，取得了以下成就 期间： 1.两种酶：(A)蔗糖6-磷酸水解酶和(B)ATP- 依赖的果糖激酶，是蔗糖发酵所必需的 Mortiferum梭杆菌这两种酶已经被提纯到 电泳性均一性。它的物理化学性质，催化 蛋白质的功能和N-端氨基酸序列已被测定 已经成立了。 2.硫转运酶在沙门氏菌致病中的作用(S) 梭杆菌正在被定义。其中一种酶，胱硫酮酶，具有 从桑寄生(F.mortiferum)中得到部分纯化。 3.禽波氏杆菌提取物对小鼠的毒性机制 哺乳动物成骨细胞已被描述，并被归因于 β-胱硫酮酶对L-胱氨酸的脱硫作用。这种酶已经被 纯化至均一，并克隆了该基因(Met C)并 已排序。 4.N(5)-编码基因的克隆、表达和测序 乳酸乳球菌的(羧乙基)鸟氨酸合成酶 完成了。 5.合成了两个新的N-(羧基烷基)氨基酸 N(5)-(CE)鸟氨酸合成酶催化的反应。 N(5)-(羧甲基)鸟氨酸和N(6)-(羧甲基)赖氨酸 纯化后，用1H、13C-核磁共振和GC-MS对其进行了表征。 6.提出了前述调查的结果，以及 在六份同行评议的出版物中进行了讨论。

This project concentrates on a basic science research program emphasizing the physiology, biochemistry, and genetic basis of regulation of amino acid and sugar fermentation pathways of oral bacteria. This fundamental knowledge is essential for identification of the causes, as well as, formulation of treatments and prevention of oral diseases. The following accomplishments have been made during this period: 1. Two enzymes: (a) sucrose 6-phosphate hydrolase, and (b) ATP- dependent fructokinase, are required for sucrose fermentation by Fusobacterium mortiferum. These two enzymes have been purified to electrophoretic homogeneity. The physicochemical properties, catalytic functions and N-terminal amino acid sequences of the proteins have been established. 2. The roles(s) of sulfur-transducing enzymes in pathogenicity of Fusobacteria are being defined. One of the enzymes, cystathionase, has been partially purified from F. mortiferum. 3. The mechanism of toxicity of extracts of Bordetella avium toward mammalian osteoblast cells has been delineated, and attributed to the desulfuration of L-cystine by beta-cystathionase. This enzyme has been purified to homogeneity, and the gene (met c) has been cloned and sequenced. 4. The cloning, expression and sequencing of the gene encoding N(5)- (carboxyethyl) ornithine synthase from Lactococcus lactis have been accomplished. 5. Two new N-(carboxyalkyl) amino acids have been synthesized via enzyme catalyzed reactions mediated by N(5)-(CE)ornithine synthase. N(5)-(Carboxymethyl) ornithine and N(6)-(carboxymethyl) lysine have been purified, and characterized by 1H,13C-NMR and GC-mass spectroscopy. 6. The results of the preceding investigations have been presented, and discussed in six peer-reviewed publications.