Composition Variation of Papain-catalyzed Esterification of a Fibroin Peptide Mixture

• Published in: Biotechnology and bioprocess engineering Vol. 16; no. 4; pp. 654 - 660
• Main Authors: Jeong, J.H., Yonsei University, Seoul, Republic of Korea, Lee, S.Y., Kangwon National University, Chuncheon, Republic of Korea, Hur, W., Kangwon National University, Chuncheon, Republic of Korea
• Format: Journal Article
• Language: English
• Published: Heidelberg The Korean Society for Biotechnology and Bioengineering 01.08.2011; Springer Nature B.V; 한국생물공학회
• Subjects: Acids; Alanine; Analysis; Bioengineering; Biotechnology; Chemical synthesis; Chemistry; Chemistry and Materials Science; Chromatography; Enzymes; ESTERIFICACION; ESTERIFICATION; Esters; fibroin peptide; Industrial and Production Engineering; Ions; Liquid chromatography; Mass spectrometry; Mass spectroscopy; PAPAIN; PAPAINA; PAPAINE; pentyl ester; Peptides; pH effects; Research Paper; Scientific imaging; selected ion monitoring; Serine; Spectrometry; Studies; Transformation; Tyrosine; valine; 생물공학; fibroin peptide; selected ion monitoring; pentyl ester; esterification; papain
• ISSN: 1226-8372; 1976-3816
• DOI: 10.1007/s12257-011-0076-9

Composition variation of a complex peptide mixture under enzymatic transformation can be tracked by mass spectrometry (MS). In this report, papain-catalyzed esterification of fibroin peptides was investigated at the individual peptide level using liquid chromatography-mass spectrometry with selected ion monitoring. Optimal conditions for maximizing ester formation were obtained using a water-to-pentanol ratio of 1:9 at pH 2.8 and 40℃; however, the optimum conditions varied for individual peptides. The optimum pH levels were 2.5 and 2.8 for the tetrapeptides with a tyrosine or a valine residue and those with alanine or serine residues, respectively. The optimum pH shifted to 3.4 for dipeptide esters with a tyrosine residue. Tetrapeptides had a relatively higher rate of esterification above 50℃. Alhough, the profiles of peptides and their esters in the esterification reaction were significantly affected by the reaction conditions, alanyl-glycine ester represented the largest fraction in the mixture under most reaction conditions. As demonstrated here, MS analysis of peptide mixtures can be used to elucidate specific reaction conditions for the enrichment of particular peptide products.