Papain purification insights: monitoring by electrophoretic approaches and MALDI-TOF peptide mass fingerprint analyses

LLERENA-SUSTER, C.R.; OBREGÓN, W.D.; TREJO, S.A.; MORCELLE, S.R.

ANALYTICAL LETTERS

TAYLOR & FRANCIS INC

Año: 2011 vol. 44 p. 2124 - 2137

0003-2719

Papain was purified from dried Carica papaya latex by fractioned salt precipitation in presence of sodium tetrathionate to preserve enzymatic activity. Purification was followed by different electrophoretic methods. Identification of the purified product was afforded by MALDI-TOF/TOF MS de novo sequencing and peptide mass fingerprint by MALDI-TOF MS. Comparison of the peptide masses analyzed by PMF MALDI-TOF and those obtained by theoretical tryptic digestion, revealed the presence of some peptides belonging the other three endopeptidases contained in Carica papaya latex (very similar to papain in molecular weight and pI) in the purified fraction of papain.