| 摘要 |
A process for obtaining high yields of recombinant protein using a ubiquitin-peptide fusion system. The system includes (1) a ubiquitin-specific protease, which cleaves only C-terminal extensions from ubiquitin, and (2) an expression system consisting of a suitable E. coli or other host strain paired with a plasmid that encodes the ubiquitin fusion. The process produces a variety of proteins and peptides including those ranging in size from 8 to 70 amino acids. The protein or peptide can be purified in a three step purification process which includes an enzymatic cleavage reaction and insures cost-effective production of gram quantities of peptides. The process typically generates over 2 grams of pure peptide from 12 grams of ubiquitin fusion, using the cell paste generated from a single 10-liter fermentation, and is readily scaled up. There is typically good correlation between increased culture volume, increased cell density and increased product yield. |
