Marcelo F. Pardo

Hieronymain I, a new cysteine peptidase isolated from unripe fruits of Bromelia hieronymi Mez (Bromeliaceae)

A new peptidase, named hieronymain I, was purified to homogeneity from unripe fruits of Bromelia hieronymi Mez (Bromeliaceae) by acetone fractionation followed by cation exchange chromatography (FPLC) on CM-Sepharose FF. Homogeneity of the enzyme was confirmed by mass spectroscopy (MALDI-TOF), isoelectric focusing, and SDS-PAGE. Hieronymain is a basic peptidase (pI > 9.3) and its molecular mass was 24,066 Da. Maximum proteolytic activity on casein (>90% of maximum activity) was achieved at pH 8.5–9.5. The enzyme was completely inhibited by E-64 and iodoacetic acid and activated by the addition of cysteine; these results strongly suggest that the isolated protease should be included within the cysteine group. The N-terminal sequence of hieronymain (ALPESIDWRAKGAVTEVKRQDG) was compared with 25 plant cysteine proteases that showed more than 50% of identity.

Comparison of two cysteine endopeptidases from Pseudananas macrodontes (Morr.) Harms (Bromeliaceae).

Abstract The properties of two cysteine peptidases (macrodontain I and II) isolated from fruits of Pseudananas macrodontes have been compared. The enzymes showed optimum pH ranges near neutrality and were inhibited by E-64 and other cysteine peptidase inhibitors. Molecular masses were 23459 and 23703 kDa, the isoelectric points were 6.1 and 5.9, and the K values were 13.4 and 8.9 M (BzPheValArg AMC) for macrodontain I and II, respectively. N? CBZLamino acid pnitrophenyl esters were tested for both enzymes. The Nterminal sequences of both proteases differed slightly and showed high sequence similarity to other pineapple stemderived cysteine endopeptidases.

Properties of a milk clotting protease isolated from fruits of Bromelia balansae Mez.

Abstract Unripe fruit extracts of Bromelia balansae Mez Bromeliaceae), whose principal endopeptidase is balansain I (isolated for anion exchange chromatography: pI = 5.45, molecular weight = 23192), exhibit pH profile with a maximum activity around pH 9.0 and are inhibited only by cysteine peptidases inhibitors. The alanine and glutamine derivatives of N?carbobenzoxy Lamino acid pnitrophenyl esters were strongly preferred by the enzyme. Enzymatic hydrolysis of milk and soy proteins yield characteristic patterns at pH 9.0. The Nterminal sequence showed very high homology (85 90%) with other known Bromeliaceae endopeptidases.