TY - JOUR
T1 - Protease-catalyzed dipeptide synthesis from N-protected amino acid carbamoylmethyl esters and free amino acids in frozen aqueous solutions
AU - Salam, Sayed Mohiuddin Abdus
AU - Kagawa, Ken ichi
AU - Matsubara, Teruhiko
AU - Kawashiro, Katsuhiro
PY - 2008/12/10
Y1 - 2008/12/10
N2 - The kinetically controlled synthesis of N-benzyloxycarbonyl (Z)-dipeptides was investigated by the use of free amino acids as nucleophiles and a cysteine protease papain as catalyst. The coupling efficiency was significantly improved by the combined use of the carbamoylmethyl (Cam) ester of a Z-amino acid as acyl donor and frozen aqueous solution (ice, -16 or -24 °C) as reaction medium. The yield of peptide synthesis became high when both P1- and P′1-positions were occupied by small non-polar amino acids (Z-Gly-Gly-OH, 76%; Z-Gly-Ala-OH, 75%; Z-Ala-Ala-OH, 72%). Similar results were observed by the use of ficin as catalyst instead of papain. Furthermore, this strategy was applied to the papain-catalyzed incorporation of a d-configured amino acid such as d-alanine into the resulting peptides. Although the coupling in aqueous solution (30 °C) afforded the desired Z-dipeptides in low yields, the freezing of reaction medium reduced significantly unfavorable hydrolysis of the acyl donors, resulting in improvement of the coupling efficiency (Z-Gly-d-Ala-OH, 80%; Z-Ala-d-Ala-OH, 45%; Z-d-Ala-Ala-OH, 22%).
AB - The kinetically controlled synthesis of N-benzyloxycarbonyl (Z)-dipeptides was investigated by the use of free amino acids as nucleophiles and a cysteine protease papain as catalyst. The coupling efficiency was significantly improved by the combined use of the carbamoylmethyl (Cam) ester of a Z-amino acid as acyl donor and frozen aqueous solution (ice, -16 or -24 °C) as reaction medium. The yield of peptide synthesis became high when both P1- and P′1-positions were occupied by small non-polar amino acids (Z-Gly-Gly-OH, 76%; Z-Gly-Ala-OH, 75%; Z-Ala-Ala-OH, 72%). Similar results were observed by the use of ficin as catalyst instead of papain. Furthermore, this strategy was applied to the papain-catalyzed incorporation of a d-configured amino acid such as d-alanine into the resulting peptides. Although the coupling in aqueous solution (30 °C) afforded the desired Z-dipeptides in low yields, the freezing of reaction medium reduced significantly unfavorable hydrolysis of the acyl donors, resulting in improvement of the coupling efficiency (Z-Gly-d-Ala-OH, 80%; Z-Ala-d-Ala-OH, 45%; Z-d-Ala-Ala-OH, 22%).
KW - Carbamoylmethyl (Cam) ester
KW - Ficin
KW - Free amino acid
KW - Frozen aqueous solution (ice)
KW - Papain
KW - Peptide synthesis
KW - d-Amino acid
UR - http://www.scopus.com/inward/record.url?scp=55949096748&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=55949096748&partnerID=8YFLogxK
U2 - 10.1016/j.enzmictec.2008.09.003
DO - 10.1016/j.enzmictec.2008.09.003
M3 - Article
AN - SCOPUS:55949096748
VL - 43
SP - 537
EP - 543
JO - Enzyme and Microbial Technology
JF - Enzyme and Microbial Technology
SN - 0141-0229
IS - 7
ER -