Journal
BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS
Volume 1572, Issue 1, Pages 10-18Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/S0304-4165(02)00277-5
Keywords
exo-polygalacturonase; Aspergillus niger; xylogalacturonan; acetylated homogalacturonan; acetylated galacturonic acid
Categories
Ask authors/readers for more resources
Two exo-polygalacturonases (EC 3.2.1.67) were purified from a commercial Aspergillus niger enzyme preparation by ammonium sulfate precipitation, preparative electrofocusing, anion-exchange and size-exclusion chromatographies. The enzymes had molar masses of 82 kDa (exo-PG1) and 56 kDa (exo-PG2). Exo-PG1 was stable over wider pH and temperature ranges than exo-PG2. Addition of 0.01 MM HgCl2 increased the exo-PG2 activity 3.4 times but did not affect exo-PG1. Analysis of the reaction products of (reduced) pentagalacturonate by high-performance anion-exchange chromatography revealed that both enzymes split the substrate from the non-reducing end in a multi-chain attack mode. Exo-PG1 had a broad specificity towards oligogalacturonates with different degrees of polymerisation, while digalacturonate was the most favorable substrate for exo-PG2. Both enzymes degraded xylogalacturonan from pea hull in an exo manner to produce galacturonic acid and Xyl-GalA disaccharide, as identified by electrospray ionization-ion trap mass spectrometry (ESI-ITMS). Moreover, exo-PGs split acetylated homogalacturonan in an exo, manner, producing galacturonic acid and acetylated galacturonic acid, as shown by ESI-ITMS. (C) 2002 Elsevier Science B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available