A protective association between catalase and isocitrate lyase in peroxisomes


Yanik T. , Donaldson R.

ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, vol.435, no.2, pp.243-252, 2005 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 435 Issue: 2
  • Publication Date: 2005
  • Doi Number: 10.1016/j.abb.2004.12.017
  • Title of Journal : ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS
  • Page Numbers: pp.243-252
  • Keywords: catalase, isocitrate lyase, glyoxysomes, hydrogen peroxidase (H2O2), protein oxidation, GLYOXYSOMAL MEMBRANES, HYDROGEN-PEROXIDE, PURIFICATION, CDNA, ACID, BIOSYNTHESIS, ENDOSPERM, PROTEINS, ENZYMES

Abstract

Glyoxysomes are specialized peroxisomes in germinating seeds, which catalyze many reactions that convert fatty acids into carbohydrates thus generating H2O2. They are characterized by the presence of catalase (CAT, E.C. 1.11.1.6) in their matrix which protects cells from oxidative stress. Here, we investigated the possibility that a protein can be protected from oxidative damage by its association with CAT. We purified peroxisomal CAT from germinating castor beans by ion exchange, gel filtration, and hydroxylapatite chromatography. Gel filtration of the matrix proteins, cross-linking, and co-immunoprecipitation studies indicate that CAT associates with a glyoxysomal matrix protein, isocitrate lyase (ICL, E.C. 4.1.3.1). In addition, we found that H2O2 inactivates ICL and degrades its product, glyoxylate, when CAT is inactive. ICL and its product appear to be sensitive to oxidative damage; thus, association of CAT with ICL would afford protection from H2O2. (C) 2004 Elsevier Inc. All rights reserved.