Characteristics of Chymotrypsin Modified with Water-soluble Acylating Reagents and Its Peptide Synthesis Ability in Aqueous Organic Media

• Published in: Bioscience, biotechnology, and biochemistry Vol. 56; no. 3; pp. 441 - 444
• Main Authors: Kawasaki, Yoshihiro, Murakami, Mototake, Dosako, Shun'ichi, Azuse, Ikunori, Nakamura, Tsutomu, Okai, Hideo
• Format: Journal Article
• Language: English
• Published: Tokyo Taylor & Francis 1992; Japan Society for Bioscience Biotechnology and Agrochemistry; Oxford University Press
• Subjects: Acylation; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Biotechnology; Catalysis; Chymotrypsin - chemistry; Chymotrypsin - metabolism; Dimethylformamide; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Hydrolases; Hydrolysis; Indicators and Reagents; Peptides - chemical synthesis; Temperature; Characterization; Chymotrypsin; Chemical modification; Enzymatic activity; Enzyme; Acylation agent; Peptide synthesis; Comparative study
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.56.441

Several kinds of modified chymotrypsin were prepared with water-soluble acylating reagents, and their characteristics after hydrolyzing with unmodified chymotrypsin in aqueous-N,N' -dimethylformamide (DMF) media were compared. It was found that chymotrypsin (Csin), of which a 20% amino group was modified with a benzyloxycarbonyl group (Z(20)Csin), had more favorable characteristics than unmodified chymotrypsin with regard to hydrolytic activity in an aqueous DMF media. We also investigated the Z(20)Csin-catalyzed peptide synthesis in two different solution systems. In the one-layer system containing water and DMF, Z(20)Csin catalyzed the peptide bond formation in a higher yield than that by unmodifide chymotrypsin and enabled a synthetic reaction in even an 80% (v/v) DMF media, in which the hydrolytic reaction could not be carried out. Z(20)Csin catalyzed the condensation between some N-acyl amino acids or peptide derivatives and amino acids in 90% ethylacetate, 90% hexane or 50% benzene. This latter method employs a two-layer system, and the modified enzyme may be able to reduce the number of synthetic steps when preparing acyl peptides.