Open AccessMembranes of Glyoxysomes from Castor‐Bean Endosperm
Author(s) -
Bieglmayer Christian,
Ruis Helmut,
Graf Jürg
Publication year - 1973
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1973.tb03018.x
Subject(s) - glyoxysome , endosperm , biochemistry , glyoxylate cycle , malate synthase , membrane , biology , microbody , chemistry , enzyme , isocitrate lyase , catalase
A procedure was developed for the isolation of membranes of glyoxysomes from the endosperm of germinating castor beans ( Ricinus communis L. var. zanzibariensis ). These membranes were prepared by osmotic‐shock treatment of isolated glyoxysomes. In some cases this was followed by mild sonication. They were isolated by centrifugation on to a 57% (w/w) sucrose layer and purified by isopycnic sucrose gradient centrifugation. The membrane preparations were characterized by electronmicroscopy and assayed for enzyme activities. They consisted mainly of ghost‐type vesicles and were found to contain a major part of fatty acid β‐oxidation, malate synthase, citrate synthase and antimycin‐A‐insensitive NADH‐cytochrome c reductase activities of the whole glyoxysomes. Malate dehydrogenase may also be bound to the membrane to a significant extent. A tentative scheme is postulated describing the structural organization of fatty acid β‐oxidation and of the glyoxylate cycle in glyoxysomes.