Structure and Functions of Polysaccharide-degrading Enzyme with High Activity under Extreme Environments

极端环境下高活性多糖降解酶的结构与功能

• 批准号: 07650952
• 负责人: NAKAMURA Satoshi
• 金额: $ 1.6万
• 依托单位: TOKYO INSTITUTE OF TECHNOLOGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650952/
• 关键词: Extremophile; Alkaline Enzyme; Xylanase; Gene Cloning; Protein Engineering; 極限微生物; アルカリキシラナーゼ

beta-1,4-Xylans are heterogeneous polysaccharides that have a backbone of beta-1,4-linked xylopyranose units. Xylanases catalyze the hydrolysis of xylan to xylooligosaccharides and xylose. Recently, The head investigator has isolated alkaliphilic Bacillus sp.strain 41M-1 from soil. Strain 41M-1 secreted a novel alkaline xylanase that had an alkaline pH optimum. The objective of this study is to elucidate the mechanism of xylan hydrolysis in alkaline conditions and to engineer the enzyme molecules for more extremophilic properties, such as alkaliphily. The head investigator cloned and sequenced the xylanase gene from strain 41M-1. The deduced amino acid sequence revealed that the xylanase consisted of an N-terminal catalytic domain and an additional functionally-unknown polypeptide region at the C-terminus. Glu-93 and Glu-183 in the catalytic domain, as well as Trp-18, Trp-86, Tyr-84 and Tyr-95, were involved in catalysis. Furthermore, the C-terminal region of the xylanase proved to be a polysaccharide-binding domain.

β-1,4-木聚糖是具有 β-1,4-连接的吡喃木糖单元主链的异质多糖。木聚糖酶催化木聚糖水解成低聚木糖和木糖。近日，课题组组长从土壤中分离出嗜碱性芽孢杆菌41M-1菌株。菌株 41M-1 分泌一种新型碱性木聚糖酶，其最适 pH 值为碱性。本研究的目的是阐明碱性条件下木聚糖水解的机制，并设计酶分子以获得更多的极端特性，例如嗜碱性。首席研究员对 41M-1 菌株的木聚糖酶基因进行了克隆和测序。推导的氨基酸序列表明，木聚糖酶由 N 端催化结构域和 C 端额外的功能未知的多肽区域组成。催化结构域中的Glu-93和Glu-183，以及Trp-18、Trp-86、Tyr-84和Tyr-95参与催化。此外，木聚糖酶的C端区域被证明是多糖结合结构域。

项目成果

Satoshi Nakamura: "Purification and characterization of a thermophilic alkaline xylanase from thermoalkaliphilic Bacillus sp.strain TAR-1" J.Mol.Catal.B:Enzymatic. 1. 7-15 (1995)

Satoshi Nakamura：“来自嗜热芽孢杆菌菌株 TAR-1 的嗜热碱性木聚糖酶的纯化和表征”J.Mol.Catal.B：酶学。

中村 聡: "微生物に由来する多糖分解酵素のコスメトロジーへの応用" コスメトロジー. 4. 109-117 (1996)

Satoshi Nakamura：“源自微生物的多糖降解酶在美容中的应用”美容学。4. 109-117 (1996)。

S.Nakamura et al.: "Purification and Characterization of a Thermophilic Alkaline Xylanase from Thermoalkaliphilic Bacillus sp.Strain TAR-1" J.Mol.Catal.B : Enzymatic. 1. 7-15 (1995)

S.Nakamura 等人：“来自嗜碱芽孢杆菌菌株 TAR-1 的嗜热碱性木聚糖酶的纯化和表征”J.Mol.Catal.B：酶学。

中村聡: "微生物に由来する多糖分解酵素のコスメトロジーへの応用" コスメトロジー. 4. 109-117 (1996)

Satoshi Nakamura：“源自微生物的多糖降解酶在美容中的应用”美容学。4. 109-117 (1996)。

大倉一郎,北爪智哉,中村聡: "生物工学英語入門" 講談社サイエンティフィク, 142 (1996)

Ichiro Okura、Tomoya Kitazume、Satoshi Nakamura：《生物工程英语导论》讲谈社科学，142（1996）