Premium
PURIFICATION AND PROPERTIES OF TWO ACID PEROXIDASES FROM BRUSSELS SPROUTS ( Brassica oleraceae L. )
Author(s) -
REGALADO C.,
ARVIZU O. PÉREZ,
GARCÍAALMENDAREZ B.E.,
WHITAKER J.R.
Publication year - 1999
Publication title -
journal of food biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 47
eISSN - 1745-4514
pISSN - 0145-8884
DOI - 10.1111/j.1745-4514.1999.tb00029.x
Subject(s) - brassica , isozyme , chemistry , peroxidase , horseradish peroxidase , chromatography , abts , biochemistry , enzyme , botany , biology , antioxidant , dpph
An acid peroxidase isoenzyme (A1) from Brussels sprouts (Brassica oleraceae L.) has been purified while another isoenzyme (A2) has been partially purified. Studies of their properties leading to a potential application in immunoassays as an alternative to horseradish peroxidase were conducted. Isoenzyme A1 was purified 503 fold, through ammonium sulfate and acetone fractionation, and successive chromatography on DEAE‐cellulose, Sephadex G‐100 and Mono‐S (FPLC system) columns. Isoenzyme A1 had a pI of 4.0, a molecular weight of 90 kDa, and contained two identical molecular weight subunits. Preliminary studies indicated a pI of 4.7 for isoenzyme A2. ABTS [2,2′‐azino‐di‐(3‐ethyl‐benzthiazoline‐6‐sulfonic acid)] K m values (0.2 mM) for both isoenzymes are 20 times lower than those reported for commercial horseradish peroxidase anionic isoenzymes. Optimum pH for activity of isoenzymes A1 and A2 were 4.3 and 4.5, respectively. Optimum temperature for isoenzyme A1 was 57C, with an activation energy for inactivation of 148.8 kJ/mol.