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Purification and catalytic properties of polygalacturonase isoforms from ripe avocado ( Persea americana ) fruit mesocarp
Author(s) -
Wakabayashi Kazuyuki,
Huber Donald J.
Publication year - 2001
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1034/j.1399-3054.2001.1130208.x
Subject(s) - persea , pectinase , polyacrylamide gel electrophoresis , molecular mass , gel electrophoresis , biochemistry , enzyme , gene isoform , chemistry , hydrolysis , gel permeation chromatography , chromatography , biology , botany , polymer , gene , organic chemistry
Endo‐polygalacturonase (PG; EC 3.2.1.15) was recovered from the cell walls of avocado mesocarp ( Persea americana Mill cv. Lula) tissue and purified by sequential ion exchange and gel permeation chromatography. Two isoforms (S‐I and S‐II) were recovered, exhibiting molecular masses of about 41 kD on size exclusion media and about 48 (S‐I) and 46 (S‐II) kDa as determined by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE). Both isoforms exhibited maximum activity at pH 6.0 against polygalacturonic acid (PGA) and hydrolyzed PGA of about 180 kDa to polymers of about 4 kDa. The catalytic activity of the 48‐kDa isoform against PGA was slightly higher than that of the 46‐kDa isoform. The purified PGs catalyzed significant molecular mass downshifts in the polyuronides of pre‐ripe avocados; however, the capacity of the enzymes to solubilize polyuronides from cell walls of pre‐ripe fruit was limited.