REGULATION OF SUGAR TRANSPORT AND METABOLISM IN LACTIC ACID BACTERIA

一种独特的依赖氨基酸的糖运输系统已经被 以革兰氏阴性口腔厌氧菌为特征的梭杆菌 核心菌ATCC 10953。活跃的人所需的能量 葡萄糖和半乳糖的运输源于厌氧 特定氨基酸(谷氨酸、赖氨酸、组氨酸)的发酵。 动力学分析和来自竞争研究的数据表明 葡萄糖和半乳糖是通过共同亲和力转运的 承运人。细胞内糖被三磷酸腺苷磷酸化- 高分子量转化前的依赖蛋白激酶 聚合物。谷氨酸、赖氨酸和组氨酸可抑制脑组织分解代谢 糖聚合物，但在没有氨基酸的情况下 聚合物被快速发酵以产生丁酸、乳酸和醋酸 酸。 鉴定和纯化了两种新的氨基酸。 乳酸链球菌。这些不寻常的氨基酸，即N(5)-(1- N(6)-(1-羧乙基)赖氨酸 化学制备和立体化学构型 天然产物已通过手性合成得到确证。入内 报道了N(5)-(1-羧乙基)-鸟氨酸的体外合成. 无细胞提取物与鸟氨酸孵育证明， 丙酮酸和NAD(P)H。 一种碱性氨基酸载体已被鉴定和表征 在乳酸链球菌的细胞中。传送者调停 赖氨酸、精氨酸和赖氨酸的能量非依赖性进入和交换 鸟氨酸。

A unique amino acid-dependent sugar transport system has been characterized in the Gram negative oral anaerobe, Fusobacterium nucleatum ATCC 10953. Energy necessary for the active transport of glucose and galactose is derived from anaerobic fermentation of specific amino acids (Glutamic, lysine, histidine). Kinetic analyses, and data from competition studies suggest that glucose and galactose are translocated via a common-affinity carrier. Intracellular sugars are phosphorylated by ATP- dependent kinases prior to conversion of high molecular-weight polymers. Glutamate, lysine and histidine prevent catabolism of the sugar polymers, but in the absence of amino acids the polymers are rapidly fermented to yield butyric, lactic and acetic acids. Two new amino acids have been identified and purified from Streptococcus lactis. These unusual amino acids, namely N(5)-(1- carboxyethyl)ornithine and N(6)-(1-carboxyethyl)lysine, have been chemically prepared and the stereochemical configurations of the natural products have been confirmed by chiral syntheses. The in vitro synthesis of N(5)-(1-carboxyethyl)-ornithine has been demonstrated by incubation of a cell-free extract with ornithine, pyruvic acid and NAD(P)H. A basic amino acid carrier has been identified and characterized in cells of Streptococcus lactis. The transporter mediates the energy-independent entry and exchange of lysine, arginine and ornithine.