title: 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 a 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-alpha-carbobenzoxy-L-amino acid p-nitrophenyl esters were strongly preferred by the enzyme. Enzymatic hydrolysis of milk and soy proteins yield characteristic patterns at pH 9.0. The N-terminal sequence showed a very high homology (85-90%) with other known Bromeliaceae endopeptidases.
authors.affiliation: LIPROVE, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Argentina.
authors.forename: M F
authors.initials: MF
authors.lastname: Pardo
authors.forename: L M
authors.initials: LM
authors.lastname: López
authors.forename: N O
authors.initials: NO
authors.lastname: Caffini
authors.forename: C L
authors.initials: CL
authors.lastname: Natalucci
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003546:Cysteine Endopeptidases / Q000302:isolation & purification / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D010450:Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D005638:Fruit / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D008892:Milk / Q000187:drug effects / Q000378:metabolism*; D008894:Milk Proteins / Q000032:analysis / Q000378:metabolism; D008969:Molecular Sequence Data; D011480:Protease Inhibitors / Q000494:pharmacology; D030262:Soybean Proteins / Q000032:analysis / Q000378:metabolism
chemical_list: D015853:Cysteine Proteinase Inhibitors; D008894:Milk Proteins; D011480:Protease Inhibitors; D030262:Soybean Proteins; D010450:Endopeptidases; C415323:balansain I; D003546:Cysteine Endopeptidases