[Sequential attachment of arginine residues to peptides catalyzed by subtilisin. II. Effect of the nature of acylating and nucleophilic components and small amounts of water in organic solvents].

The reaction of Dnp(or Z)-Ala2-Xaa-OCH3 (Xaa = Ile of Val) with arginine amide or p-nitroanilide was studied in organic solvents, which was catalyzed by subtilisin sorbed on macroporous glass, It resulted in the formation of peptides containing one to four arginine residues: Dnp(or Z)-Ala2-Xaa-(Arg) 1-4-NH2. The number of arginine residues attached to the peptide depended on the water content in organic solvents, nature of the amino acid residue Xaa in the P1 position of the acylating component, and the type of the N-protective group. The reaction can be used for synthesizing arginine-containing substrates of convertases and cathepsins B, L, and O. A chromogenic substrate for duodenase Z-Ala2-Ile-Arg2-pNA was obtained.