Peptides enzymatic synthesis - by reacting peptide free acids with amino acids or peptides in the presence of pepsin

摘要

Peptides fo the formula X-A-B-C-Y (I) (where A is Ala, Gln, Asn, omega-Boc-Lys, Leu, Gly, Glu, Glu or Pro, or is a gp. A1-A2 in which A1 is a hydrophilic amino acid residue and A2 si Val, Met, Leu or Glu; B is Phe, Tyr, Leu, Met, Glu, Asp, Gln, Asn or Trp; C is Phe, Leu, lleu, Tyr, Cys- SBzl, Ser-OBzl, Trp or Met; X is an alpha-aminoacid protecting gp. or an amino acid or peptide residue carrying a protecting gp. on its N-terminal; and Y is a carboxyl-protecting gp. or an amino acid or peptide residue carrying a protecting gp. on its C-terminal) (e.g. alpha, omega-Boc-Lys-Phe-Gly-Leu- Met-NH2) are prepd. by reacting peptides of the formula X-A-B-OH (II) (e.g. alpha,omega-Boc-Lys-Phe-OH) with an amino acid or peptide of the formula H-C-Y (III) (e.g. HCL, H-Phe- Gly-Leu-Met-NH2) in the presence of the enzyme pepsin. High yields are obtd.