Characteristics of chymotrypsin modified with water-soluble acylating reagents and its peptide synthesis ability in aqueous organic media.
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.
Technical Research Institute, Snow Brand Milk Products Co., Ltd., Kawagoe, Japan.
Y
Y
Kawasaki
M
M
Murakami
S
S
Dosako
I
I
Azuse
T
T
Nakamura
H
H
Okai
D000215:Acylation; D002384:Catalysis; D002918:Chymotrypsin / Q000737:chemistry / Q000378:metabolism*; D004126:Dimethylformamide; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007202:Indicators and Reagents; D010455:Peptides / Q000138:chemical synthesis*; D013696:Temperature
D007202:Indicators and Reagents; D010455:Peptides; D004126:Dimethylformamide; D002918:Chymotrypsin