Interaction of the AMP deaminase-ammonium system with glutamate dehydrogenase in yeast.
NH+4 produced as a result of the activation of AMP deaminase (AMP aminohydrolase, EC 3.5.4.6) was utilized effectively to form glutamate from 2-oxoglutarate by the action of NADP-glutamate dehydrogenase (L-glutamate:NADP+ oxidoreductase (deaminating), EC 1.4.1.4) under in situ conditions in yeast cells: the decrease in total adenylates stoichiometrically corresponded to the production of NH+4 plus glutamate. Reducing equivalents, NADPH, for the synthesis of glutamate can be supplied by the pentose phosphate pathway. The addition of spermine, an activator of AMP deaminase without changes in glutamate dehydrogenase activity, resulted in an increase in ammonium concentration, which can enhance the formation of glutamate from 2-oxoglutarate. A close correlation of NADP-glutamate dehydrogenase with AMP deaminase activity was observed under various growth conditions. The interaction of the AMP deaminase-ammonium system with glutamate dehydrogenase as an ammonium-assimilating reaction may participate in the control of the cellular NH+4 level, which can correlate with glycolysis.
D000659:AMP Deaminase / Q000378:metabolism*; D000641:Ammonia / Q000378:metabolism*; D002175:Candida; D005969:Glutamate Dehydrogenase / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D009709:Nucleotide Deaminases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D013997:Time Factors
D009243:NAD; D009249:NADP; D000641:Ammonia; D005969:Glutamate Dehydrogenase; D009709:Nucleotide Deaminases; D000659:AMP Deaminase