ENZYMES IN PEROXISOMES

Peroxisomes from spinach leaves containing enzymes related to glycolate metabolism.

Microbodies, designated as peroxisomes because of their enzyme complement, have been isolated from spinach leaves. After grinding leaves in 0.5 M sucrose, the peroxisomes were removed with the broken chloroplast fraction by differential centrifugation. During sucrose density gradient centrifugation, the peroxisomes banded in about 1.9 M sucrose and were separated from mitochondria and chloropla...

Distribution of tricarboxylic acid cycle enzymes and glyoxylate cycle enzymes between mitochondria and peroxisomes in Tetrahymena pyriformis.

Tetrahymena Pyriformis cells were grown axenically, harvested in the stationary phase of the cultures when the organism is glyconeogenetically active, homogenized, and fractionated either by isopycnic density gradient centrifugation in a sucrose gradient or by zonal differential sedimentation through a sucrose gradient. Protein and enzyme determinations carried out on the fractions led to the f...

Absence of functional peroxisomes does not lead to deficiency of enzymes involved in cholesterol biosynthesis.

To unravel the conflicting data concerning the dependence of human cholesterol biosynthesis on functional peroxisomes, we determined activities and levels of selected enzymes involved in cholesterol biosynthesis in livers of PEX5 knockout mice, a well-characterized model for human Zellweger syndrome. We found that all enzymes measured, including putative peroxisomal enzymes, are at least as act...

Localization of enzymes of ureide biosynthesis in peroxisomes and microsomes of nodules.

The intracellular location of enzymes involved in the synthesis of the ureides, allantoin and allantoic acid, was investigated in nodules of Glycine max L. Merr. Cellular organelles were separated on isopycnic sucrose density gradients. Xanthine dehydrogenase activity (270 nanomoles per min per gram fresh weight) was totally soluble, whereas approximately 15% of the total uricase and catalase a...

Lipid biosynthesis in peroxisomes.