Hieronymain II, a new peptidase from fruits of Bromelia hieronymi Mez (Bromeliaceae)

BRUNO, MARIELA A; STABILE, Mª DE LAS MERCEDES ,; MERCERAT, JULIO R. ,; CAFFINI, NÉSTOR O.; LÓPEZ, LAURA M.I

San Carlos de Bariloche

Congreso; XXXIX Reunión Anual de la Sociedad Argentina de Investigaiones en Bioquímica y Biología Molecular; 2003

SAIB

The best known family of cysteine peptidases is the papain family, which contains endopeptidases with broad specifity (such as papain), or a narrow specifity (such as glycyl endopeptidase), aminopeptidases, and peptidases with both endo- and exopeptidase activities. Most plant cysteine peptidases belong to the papain family, including those of Bromeliaceae. From unripe fruits of Bromelia hieronymi Mez (Bromeliaceae) a new peptidase, named hieronymain II, was purified to homogeneity by acetone fractionation followed by anionic exchange chromatography (FPLC) on Q- Sepharose HP and rechromatographied employing the same exchanger but different saline gradient. Homogeneity of the enzyme was confirmed by isoelectric focusing-zymogram. Hieronymain II is a basic peptidase (pI 8.3) and its molecular mass was 25 kDa (SDS-PAGE). Maximum proteolytic activity on casein (more than 90% of maximum activity) was achieved at pH 7.5-9.0. The enzyme was completely inhibited by E-64 and iodoacetic and activated by the addition of cysteine; these results strongly suggest that the isolated protease should be included within the cysteine group. 1 CIC and 2CONICET Researcher Career. Supported by grants from ANPCyT, CONICET, CIC, UNLP and CYTED.