SUMO Fusions to Enhance Protein Expression & Secretion

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.