Claims for Patent: 4,086,136

Summary for Patent: 4,086,136

Title:	Process for producing a peptide using a serine or thiol proteinase
Abstract:	A peptide having the formula wherein A and B are the same or different and each represents an amino acid residue or a peptide residue, X represents an amino protective group, Y represents a carboxyl protective group selected from the group consisting of tertiary alkoxy, and benzyloxy, benzylamino and benzhydrylamino which can be substituted with an inert substituent, is prepared by a process which comprises reacting an amino acid or peptide having an N-terminal protective group, or a salt thereof of the formula: with an amino acid or peptide having a C-terminal protective group or a salt thereof of the formula: in the presence of a thiol proteinase or serine proteinase enzyme in an aqueous solution having a pH sufficient to maintain the enzyme activity of said thiol proteinase or serine proteinase.
Inventor(s):	Isowa; Yoshikazu (Tokyo, JA), Ohmori; Muneki (Tokyo, JA), Kurita; Hideaki (Sagamihara, JA), Ichikawa; Tetsuya (Sagamihara, JA), Sato; Masanari (Sagamihara, JA), Mori; Kaoru (Sagamihara, JA)
Assignee:	(Zaidanhojin) Sagami Chemical Research Center (Tokyo, JA)
Application Number:	05/732,543
Patent Claims:	1. A process for producing a peptide having the formula wherein A and B are the same or different and represent an amino acid residue or a peptide residue; X represents an amino protective group; and Y represents a carboxyl protective group selected from the group consisting of tertiary alkoxy, and benzyloxy, benzylamino and benzhydrylamino which can be substituted with an inert substituent, which comprises: reacting an acid component of an amino acid or peptide having N-terminal protective group or a salt thereof of the formula X-A-OH with an amino component of an amino acid or peptide having a C-terminal protective group or a salt thereof of the formula in the presence of a thiol proteinase or serine proteinase enzyme in an aqueous solution having a pH sufficient to maintain the enzyme activity of said thiol proteinase or serine proteinase. 2. The process of claim 1, wherein said thiol proteinase is papain, Stembromelein, Ficin, Cathepsin B, Chymopapain, or Streptococcal proteinase and said serine proteinase is subtilisin, Aspergillus alkaline proteinase, Elastase, .alpha.-Lytic proteinase or Chymotryspin. 3. The process of claim 1, wherein the pH is maintained at a sufficient level by reacting the amino acid or peptide reactants in a buffer solution at a pH of 4 to 7.5 for the thiol proteinase and 6 to 9 for the serine proteinase. 4. The process of claim 1, wherein the pH is maintained at the desired level by detecting the pH of the reaction mixture and adding an acid or a base to said aqueous solution depending upon the measured pH of the reaction mixture. 5. The process of claim 1, wherein the reaction is conducted with a reactant ratio of 0.8 to 2 moles of the acid component per mole of the amine component. 6. The process of claim 1, wherein the reaction is conducted by adding 10 to 500 mg of said thiol proteinase or serine proteinase to said solution per mmole of said amine component. 7. The process of claim 1, wherein the N-terminal protective group of the acid component is a tertiary alkoxycarbonyl group or a benzyloxycarbonyl group which can be substituted with an inert substituent, p-toluenesulfonyl or o-nitrophenyl sulfenyl, and the C-terminal protective group of the amine component is tertiary alkoxy, benzyloxy (--OBzl), p-nitrobenzyloxy [--OBzl (p-NO.sub.2)], benzhydryloxy, (--OBzh), benzylamino (--NHBzl), 2,4-dimethoxybenzylamino (--NHDMB), benzhydrylamino(--NHBzh) which can be substituted with an inert substituent. 8. The process of claim 7, wherein said tert-alkoxycarbonyl group is t-butyloxycarbonyl, or t-amyloxycarbonyl; said substituted benzyloxycarbonyl is p-methoxybenzyloxycarbonyl, 3-5-dimethoxybenzyloxycarbonyl, p-phenylazobenzyloxycarbonyl, or 2,4,6-trimethylbenzyloxycarbonyl, said tertiary alkoxy group is t-butoxy, and said inert substituent of said benzyhydrylamino group is 2,4-dimethoxyoxybenzylamino or benzyhydrylamino. 9. The process of claim 1, wherein A and B are the same or different and represent an amino acid residue or peptide residue wherein the amino acid is an aliphatic amino acid, an oxyamino acid, a sulfur-containing amino acid, a monoamino dicarboxylic acid, a diamino monocarboxylic acid, an aromatic amino acid or a heterocyclic amino acid. 10. The process of claim 9, wherein said aliphatic amino acid is a monoaminomonocarboxylic selected from the group consisting of glycine, alanine, valine, norvaline, leucine, isoleucine, and norleucine, said oxyamino acid is serine, threonine or homoserine; said sulfur-containing amino acid is methionine, cystine or cysteine; said monoamino dicarboxylic acid is aspartic acid or glutamic acid; said diamino monocarboxylic acid is ornithine, lysine, or arginine; said aromatic amino acid is phenylalanine or tyrosine, and said heterocyclic amino acid is histidine or tryptophan.

Details for Patent 4,086,136

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Discure Medical, Llc	CHYMODIACTIN	chymopapain	For Injection	018663	11/10/1982		2040-04-01
Discure Medical, Llc	CHYMODIACTIN	chymopapain	For Injection	018663	08/21/1984		2040-04-01