Carbon metabolism.
Explore the source record for details and available documents.
Aspergillus nidulans↗
Biomedical subjects
D H Hondmann
Publications and source records attributed to D H Hondmann.
Glycerol catabolism in Aspergillus nidulans.
Glycerol is catabolized in Aspergillus nidulans by glycerol kinase and a mitochondrial FAD-dependent sn-glycerol 3-phosphate dehydrogenase. The levels of both enzymes are controlled by carbon catabolite repression and by specific induction. Biochemical and genetical analyses show that dihydroxyacetone and D-glyceraldehyde are converted into glycerol and then catabolized by the same pathway. D-Glyceraldehyde can be reduced by NADP(+)-dependent glycerol dehydrogenase or by alcohol dehydrogenase I, while dihydroxyacetone is only reduced by the first enzyme. Three new glycerol non-utilizing mutants have been found. These three mutations define three hitherto unknown loci, glcE, glcF and glcG. The mutation in glcG leads to a greatly decreased sn-glycerol-3-phosphate dehydrogenase activity.
Alcohol Dehydrogenase↗
Screening method for large numbers of dye-adsorbents for enzyme purification.
A method is described by means of which 96 different dye-adsorbents can be tested simultaneously for their ability to bind enzymes and to test their biospecific elution. Small amounts of cell-free extract are applied to dye-adsorbents which are packed in a 96-well transplate cartridge. After biospecific elution, the amount of the eluted enzyme is tested in a microtitre plate assay. The method is illustrated by the purification of glycerol dehydrogenase (E.C. 1.1.1.72), 6-phosphogluconate dehydrogenase (E.C. 1.1.1.44) and glucose-6-phosphate dehydrogenase (E.C. 1.1.1.49) from the hyphal fungus Aspergillus nidulans.
Aspergillus nidulans↗
A translocation activating the cryptic nitrogen regulation gene areB inactivates a previously unidentified gene involved in glycerol utilisation in Aspergillus nidulans.
The chromosome VIII translocation breakpoint of the areB-404 translocation, selected for its ability to activate the cryptic nitrogen metabolism regulatory gene areB, and the mutation glcD-100 both lead to loss of mitochondrial FAD-dependent sn-glycerol-3-phosphate dehydrogenase in Aspergillus nidulans. These two lesions therefore define glcD, a second gene (in addition to glcB) where mutation can result in loss of this enzyme. The glcD gene has been localised to a centromere-proximal region of the right arm of chromosome VIII. Although all six known areB-activating mutations involve chromosomal rearrangements and presumably therefore gene fusions, areB-404 is the first such rearrangement where the gene involved in an areB fusion has been identified.
Aspergillus nidulans↗
Purification and properties of NADP(+)-dependent glycerol dehydrogenases from Aspergillus nidulans and A. niger.
Glycerol dehydrogenase, NADP(+)-specific (EC 1.1.1.72), was purified from mycelium of Aspergillus nidulans and Aspergillus niger using different purification procedures. Both enzymes had an Mr of approximately 38,000 and were immunologically cross-reactive, but had different amino acid compositions and isoelectric points. For both enzymes, the substrate specificity was limited to glycerol and erythritol for the oxidative reaction and to dihydroxyacetone (DHA), diacetyl, methylglyoxal, erythrose and D-glyceraldehyde for the reductive reaction. The A. nidulans enzyme had a turnover number twice that of the A. niger enzyme at pH 6.0, whereas inhibition by NADP+ was less (Ki = 45 microM vs 13 microM). It is proposed that both enzymes catalyse in vivo the reduction of DHA to glycerol and that they are regulated by the anabolic reduction charge.
Amino Acids↗