Chemical synthesis of long or aggregation-prone peptide has been problematic. Its biological production has an advantage in that point, but it often forms inclusion body which creates difficulties in recovery of targets. As a deubiquitylating enzyme (Usp2-cc) was shown in this study to maintain its activity even in the presence of up to 4 M urea, target peptide was purified by a single step of chromatography after overexpression as inclusion body, solubilization in urea and cleavage by the enzyme from the fusion protein consisting of GroES (used for high expression and easy to handle), ubiquitin (as a cleavage site) and target peptide. This system is a convenient tool for production of peptides that are difficult to be chemically synthesized and biologically purified. (c) 2007 Elsevier Inc. All rights reserved.