Glycolate metabolism and subcellular distribution of glycolate oxidase in Spatoglossum pacificum (Phaeophyceae, Chromophyta)

Authors


  • Communicating editor: T. Horiguchi.

SUMMARY

Seven enzymes participating in glycolate metabolism were demonstrated to be present in crude extract of the brown alga Spatoglossum pacificum Yendo. These were phosphoglycolate phosphatase, glycolate oxidase, glutamate-glyoxylate aminotransferase, serine hydroxymethyltransferase, amino acid-hydroxy-pyruvate aminotransferase, hydroxypyruvate reductase and catalase. Malate synthase, which is involved in glycolate metabolism in the xanthophycean alga, could not be detected.

On demonstration of subcellular distribution of glycolate oxidizing enzymes by linear sucrose density gradient centrifugation, glycolate oxidase was detected in the same fraction at a density of 1.23 g cm−3 with catalase: that is, the marker enzyme of peroxisome and serine hydroxymethyltransferase was found in the same fraction at a density of 1.21 g cm−3 with isocitrate dehydrogenase, the marker of mitochondria. From the present data, it is proposed that the brown alga Spatoglossum possesses the ability to metabolize glycolate to glycerate via the pathway which may be similar to that of higher plants.

Ancillary