Dipeptide synthesis in biphasic medium: evaluating the use of commercial porcine pancreatic lipase preparations and the involvement of contaminant proteases

Journal of the Brazilian Chemical Society

Cleber W. Liria¹  Carolina D. Romagna¹  Nicolas N. Rodovalho¹  Sandro R. Marana¹  M. Terêsa M. Miranda¹ 

[1] ,Universidade de São Paulo Instituto de Química Departamento de BioquímicaSão Paulo SP ,Brazil

关键词: biocatalysis;    enzymes;    peptide bond synthesis;    n-hexane;   

DOI  :  10.1590/S0103-50532008000800018

来源: SciELO

【 摘 要 】

Dipeptide syntheses starting from Ac-L-Tyr-OEt or Z-L-X-OMe (X: Asp, Tyr, Phe, Arg, Lys or Thr) and glycine amide in biphasic reaction media were achieved using two commercially available porcine pancreatic lipase (PPL) preparations (crude (cPPL) and purified PPL (pPPL)). Under the mild conditions employed, α-chymotrypsin, a pancreatic protease that also presents esterase activity, catalyzed Ac-L-Tyr-Gly-NH2 synthesis with high productivity. Product hydrolysis also occurred in most of the syntheses studied. Polyacrylamide gel electrophoresis, enzymatic assays employing specific chromogenic substrates and size-exclusion chromatography revealed that cPPL and pPPL contain contaminant proteases and, therefore, exhibit esterase and amidase activities. Overall, these data indicate that those contaminants may be the main catalysts of peptide bond synthesis when Nα-blocked-L-amino acid esters and the commercial PPL preparations are used. On the other hand, such data do not contest the possibility of using such enzyme preparations as an inexpensive source of catalysts for dipeptide synthesis under soft conditions.

【 授权许可】

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