Penduliflorain I: A Cysteine Protease Isolated from Hohenbergia penduliflora (A.Rich.) Mez (Bromeliaceae)

PÉREZ A; CARVAJAL C; TREJO S; TORRES M J; MARTIN M I; LORENZO J C; NATALUCCI C L; HERNÁNDEZ M

The protein journal

SPRINGER

Año: 2010 vol. 29 p. 225 - 233

1875-8355

Penduliflorain I, a new plant endopeptidase, was isolated and characterized from Hohenbergia penduliflora. Crude extract was obtained from stems. A partially purified enzyme preparation was obtained by ethanol precipitation. This preparation showed maximum activity between pH 7.5 and 8.5, was stable at ionic strength (20% decrease in proteolytic activity could be detected after 2 h in 0.4 M sodium chloride solution), and exhibited high thermal stability (inactivation required heating for 20 min at 75ºC). Inhibition and activation assays indicated the cysteine nature of the enzymatic preparation. Penduliflorain I was purified by anion exchange chromatography (Q-Sepharose HP) by FPLC system. Homogeneity was confirmed by mass spectroscopy. Molecular mass of the enzyme was 23 412.847 Da (MALDITOF–MS). Kinetic parameters were determined for PFLNA (Km = 0.3227 mM and kcat = 4.27 s-1). The N-terminal sequence (AVPQSIDWRDYGAVTTDKNQ) of isolated protease showed considerable similarity to other cysteine proteases obtained from stems or fruits of different Bromeliaceae species.