Penduliflorain i: a new papain-like cysteine peptidase isolated from Hohenbergia penduliflora stems

PÉREZ A., CARVAJAL C., TREJO S.A., TORRES M.J., MARTÍN M.I., NATALUCCI C.L., JORRIN J. Y HERNÁNDEZ M.

Ciego de Avila, Cuba

Congreso; VI International Congress on Biotechnology and Agriculture; 2007

Plants are equipped with large proteolytic machinery that irreversibly regulates the fate of proteins. Proteinases also participate in the recognition of pathogens and pest and the induction of effective defense response (1). These enzymes are extensively used in many industrial processes and their pharmaceutical applications have been described for ages (2 y 3). Several plant cysteine proteases from Bromeliaceae family have been reported. Nowadays, considerable attention has been focused on the possibility to find new sources to obtain similar proteasas. In the present study, cysteine proteases were isolated from Hohenbergia penduliflora Mez stems. A new acid papain-like cysteine peptidase was purified by ethanol fractionation followed by anion exchange chromatography (QSepharose HP) using FPLC system. Purification factor was 3.55-fold and yield was high (60.1%). Homogeneity was confirmed by SDS-PAGE and mass spectroscopy (MS). Molecular mass of the enzyme was 23 412.00 Da (MALDI-TOF), its isoelectric point was . 4.5. Endopeptidase activity was measured using N-á-carboxibenzoil-L-aminoacid-pnitrophenyl ester as substrate. The alanine derivate was strongly preferred by enzyme. Kinetic parameters were determined for N-á-carboxibenzoil-L-ala-p-nitrophenyl (Km=0,0721 mM and kcat=11.063 s–1). The N-terminal sequence of isolated proteases showed considerable similarity to other cysteine proteases obtained from different Bromeliaceae species.