Function and structure of glucosyltransferase of Streptococcus sobrinus

远缘链球菌葡萄糖基转移酶的功能和结构

• 批准号: 06671811
• 负责人: FUKUI Kazuhiro
• 金额: $ 1.28万
• 依托单位: Okayama University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06671811/
• 关键词: Streptococcus sobrinus; function asd structure; glucosyltransferase; water-insoluble glucan; alpha-1,3 glucan; dextran-dependent; glucosyltransferase; streptococcus mutans; グルカン合成酵素遺伝子

Streptococcus sobrinus produce water-insoluble glucanthase which acts on sucrose to form insoluble glucan by tacking on alpha-1,3 linked branch along the alpha-1,6 chain of dextran. In this study, evidence is presented that S.sobrinus 6715 GTF-I performs the dextran-independent alpha-1,3 glucan formation using sucrose as a sole substrate. The enzyme preparation used a subfragment of GTF-I^1 obtained by a molecular cloning method, which lacks some amino acid residues bothe in N- and C-terminal regions of whole GTF-I peptide but rapidly produces insoluble glucans as does the GTF-I if primer dextran are present. When GTF-I^1 was incubated with sucose added glucose or nigerose, nigerose enhance the sucrose splitting and glucosyl transfer reaction, but glucose did not enhance so much sucrose splitting reaction in spite of acceleration of glucosyl transfer reaction.The results these experiments suggest a possibility that the glucosyl transfer first occurs to glucose forming (glc) 2 or nigerose, which in turn serves as the glucosyl acceptor to form (glc) 3 and so on.

远缘链球菌产生不溶于水的葡聚糖酶，该酶作用于蔗糖，沿着葡聚糖链的α-1，3连接支链作用于蔗糖形成不溶性葡聚糖。在这项研究中，有证据表明，远缘链霉菌6715 GTF-I以蔗糖为唯一底物进行不依赖于葡聚糖的α-1，3葡聚糖的形成。该酶制剂使用分子克隆方法获得的GTF-I^1亚段，在整个GTF-I肽的N-末端和C-末端都缺少一些氨基酸残基，但在有引发物葡聚糖存在的情况下，可以像GTF-I一样迅速产生不溶性葡聚糖。当GTF-I^1与蔗糖加葡萄糖或黑糖孵育时，黑糖促进了蔗糖裂解和葡萄糖转移反应，而葡萄糖虽然加速了葡萄糖转移反应，但对蔗糖裂解反应的促进作用不大。这些实验结果表明，葡萄糖转移可能首先发生在葡萄糖形成(GLC)2或黑糖，然后作为葡萄糖受体形成(GLC)3等。

项目成果

Norifumi Konishi: "Structure and function of Streptococcus sobrinus water-insoluble glucan synthase (glucosyltransferase-I)" The Journal of Okayama Dental Society. 13. 195-207 (1994)

小西纪文：“远缘链球菌水不溶性葡聚糖合酶（葡糖基转移酶-I）的结构和功能”冈山牙科学会杂志。

Norifumi Konishi, Kiyoshi Inoue, Tatsuo Yamamoto, Atsushi Miyagi, Hiroyuki Ohta, Yasuhiro Rorii, Tatsuo Watanabe, Kazuhiro Fukui and Takao Kodama: "De Novo synthesis of alpha-1,3 glucans from sucrose by water-insoluble gulucan synthase of cariogenic Strep

Norifumi Konishi、Kiyoshi Inoue、Tatsuo Yamamoto、Atsushi Miyagi、Hiroyuki Ohta、Yasuhiro Rorii、Tatsuo Watanabe、Kazuhiro Fukui 和 Takao Kodama：“通过致龋链球菌的水不溶性葡聚糖合酶从蔗糖中从头合成 α-1,3 葡聚糖

Norifumi Konishi: "De Novo Synthesis of α-1,3 Glucans from Sucrose by Water-Insoluble Glucan Synthase of Cariogenic Streptococcus sobrinus" Microbiology. in submission.

Norifumi Konishi：“通过致龋链球菌的水不溶性葡聚糖合酶从蔗糖中从头合成 α-1,3 葡聚糖”微生物学。

小西 法文: "Streptococcus sobrinus不溶性グルカン合成酵素の構造と機能" 岡山歯学会雑誌. 13. 195-207 (1994)

小西纪文：“远缘链球菌不溶性葡聚糖合酶的结构和功能”冈山牙科学会杂志 13. 195-207 (1994)。