Study of an extremophilic ß-endoglucanase

极端微生物α-内切葡聚糖酶的研究

• 批准号: 33995745
• 负责人: Privatdozent Dr. Georg Lipps
• 金额: --
• 依托单位: Centre de Recherche sur les Macromolécules Végétales UPR CNRS 5301
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/33995745?language=en
• 关键词: Study; extremophilic; endoglucanase

The ß-endoglucanase SSO1949 from Sulfolobus solfataricus is an extremophilic enzyme with outstanding properties. This enzyme has its highest activity at pH 1.8 and 80 °C, and it is more stable under acidic conditions than at neutrality. Such a combination of extremophilic properties has not been reported for any other ß-endoglucanase. For the production of fermentable sugars from cellulosic biomass, an acidophilic ß-endoglucanase could be of great advantage since the raw biomass must be pretreated which is most commonly done with acids. In this application we want to investigate the biochemical and structural details which form the basis of the extremely low pH optimum of SSO1949 and we intend to improve the catalytic efficiency of SSO1949 against crystalline or acid-swollen cellulose. We will construct mutants with amino acid changes at the active site and study the activity of the mutants. To rationalize the effects of amino acid changes, a crystal structure of SSO1949 would be valuable and is also part of this project. Moreover we will study the stability of SSO1949 under acidic conditions with unfolding experiments in order to understand the high stability of the enzyme at low pH. Furthermore we will construct fusions of the catalytic domain of SSO1949 with carbohydrate binding modules in order to improve the catalytic efficiency against cellulose. Finally we will randomly generate mutant enzyme and screen them for increased enzymatic activity. The application combines basic research in enzymology with applied research for the use of heat- and acid-stable ß-endoglucanase for cellulose depolymerisation.

来自磺胺溶液的ß-核葡聚糖酶SSO1949是一种具有出色特性的极端美感酶。该酶在pH值为1.8和80°C时具有最高的活性，并且在酸性条件下比中性更稳定。对于任何其他β-内核糖酶，尚未报道过极端美感特性的这种组合。为了从纤维素生物量生产可发酵糖，由于必须预处理原始生物质，这是最常见的，这是用酸来完成的。在此应用中，我们希望研究构成SSO1949极低最佳最佳最佳基础的生化和结构细节，我们打算提高SSO1949对晶体或酸溶剂纤维素的催化效率。我们将在活性位点构建具有氨基酸变化的突变体，并研究突变体的活性。氨基酸变化的影响，SSO1949的晶体结构很有价值，也是该项目的一部分。此外，我们将通过展开的实验研究SSO1949在酸性条件下的稳定性，以了解低pH值时酶的高稳定性。此外，我们将构建SSO1949催化结构域与碳水合物结合模块的融合，以提高针对纤维素的催化效率。最后，我们将随机生成突变酶，并筛选它们以增加酶活性。该应用将酶学中的基础研究与应用研究的基础研究结合在一起，用于将热和酸稳定的ß-核谷敦酶用于纤维素解聚。