ISSN:
1432-072X
Keywords:
Peroxisomes (microbodies)
;
Saccharomyces cerevisiae
;
Catalase
;
Urate oxidase
;
Glyoxylate cycle
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Peroxisomes were isolated from derepressed (lactose grown) Saccharomyces cerevisiae cells following homogenization with a “Merkenschlager” cell mill (at 0°C using glass beads). Catalase and urate oxidase, along with low activities of d-amino acid oxidase and l-α-hydroxyacid oxidase (glycollate oxidase), were associated with the peroxisomes. No catalase activity was present in glucose repressed cells. When protoplasts prepared from derepressed cells were used for peroxisome isolation, catalase activity was not sedimentable through gradients. Apparently peroxisomes were destroyed as the cells became fermentative during protoplast preparation. The distribution of glyoxylate cycle enzymes was examined. Isocitrate lyase was not sedimentable, suggesting that, if the enzyme is peroxisome-associated, it is either readily released or present in a labile second class of peroxisomes. Low activities of malate dehydrogenase and citrate synthetase were found in peroxisome fractions from gradients, but may represent mitochondrial contamination. Citrate synthetase was not found associated with a low-density particle as had been previously reported.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00447136
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