SUMO Fusions to Enhance Protein Expression & Secretion

描述（由申请人提供）：随着从基因组测序项目中鉴定出更多的蛋白质，越来越需要用于表达和纯化具有学术和临床重要性的蛋白质的可靠且具有成本效益的方法。LifeSensors公司开发了一种新型的SUMO融合系统，以增强多种蛋白在大肠杆菌中的表达和溶解度。大肠杆菌，并通过连接到SUMO的亲和标签促进蛋白质的下游纯化。该系统的一个重要特征是从表达的蛋白质中切割SUMO融合蛋白的蛋白酶。融合物的去除不留下N-末端突出端，使得任何所需的氨基酸可以克隆在表达的蛋白质的N-末端。一些研究或治疗上重要的蛋白质在细菌中不能很好地表达或不能有效地分泌。我们建议利用SUMO的伴侣特性来增强蛋白质在大肠杆菌中的表达和分泌。为了扩展SUMO融合技术的应用，将在SUMO的N-末端引入分泌信号。枯草芽孢杆菌（Bacillus subtilis）和乳酸乳球菌（Lactococcus lactis）因其分泌特性而众所周知并广泛用于食品工业，然而这些细菌尚未被开发用于生物制药工业中的蛋白质分泌。LifeSensors提出了SUMO基因融合系统在枯草芽孢杆菌和乳酸乳球菌中增强模型蛋白表达和分泌的有用性。

DESCRIPTION (provided by applicant): As more proteins are identified from the genome-sequencing projects, there is an increasing need for reliable and cost efficient means for expression and purification of proteins of academic and clinical importance. LifeSensors has developed a novel SUMO-fusion system to enhance expression, and solubility of a wide variety of proteins in E. coli, and to facilitate the downstream purification of the protein via an affinity tag attached to SUMO. An important feature of the system is the protease that cleaves the SUMO-fusion from expressed proteins. Removal of the fusion leaves no N-terminal overhang so that any desired amino acid can be cloned at the N-terminus of the expressed protein. Several research or therapeutically important proteins do not express well in bacteria or inefficiently secreted. We propose to exploit the chaperoning properties of SUMO to enhance expression and secretion of proteins in E coli. To extend the utility of the SUMO-fusion technology, a secretion signal will be introduced at N-terminal of SUMO. Bacillus subtilis and Lactococcus lactis, are well known for their secretory properties and widely used in food industry and yet these bacteria have not been exploited for protein secretion in biopharmaceutical industry. LifeSensors proposes the usefulness of SUMO-gene fusion system to enhance expression and secretion of model proteins in Bacillus subtilis and Lactococcus lactis.