Characterization of the oxaloacetate decarboxylase and pyruvate kinase-like activities of Saccharomyces cerevisiae and Anaerobiospirillum succiniciproducens phosphoenolpyruvate carboxykinases.
Two members of the ATP-dependent class of phosphoenolpyruvate carboxykinases (PEPCKs) (Saccharomyces cerevisiae and Anaerobiospirillum succiniciproducens) have been comparatively studied with regard to their oxaloacetate (OAA) decarboxylase and pyruvate kinase-like activities. The pyruvate kinase-like activities were dependent on the presence of Mn2+; at the same concentrations Mg2+ was not effective. These activities were synergistically activated by a combination of both metal ions. Vmax for these activities in A. succiniciproducens and S. cerevisiae PEPCKs was 0.13% and 1.2% that of the principal reaction, respectively. The OAA decarboxylase activity was nucleotide independent and, with decreasing order of effectiveness, these activities were supported by Mn2+ and Mg2+. AMP is an activator of these reactions. Vmax for the OAA decarboxylase activities in A. succiniciproducens and S. cerevisiae PEPCKs was 4% and 0.2% that of the PEP-forming reaction, respectively.
Jabalquinto
A M
AM
Departamento de Ciencias Químicas, Facultad de Química y Biología, Universidad de Santiago de Chile. jabalquinto@quimbio.usach.cl
Laivenieks
M
M
Zeikus
J G
JG
Cardemil
E
E
D000227:Adenine Nucleotides / Q000378:metabolism; D002262:Carboxy-Lyases / Q000378:metabolism*; D002384:Catalysis; D006089:Gram-Negative Anaerobic Bacteria / Q000201:enzymology*; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D019764:Phosphoenolpyruvate Carboxykinase (ATP) / Q000378:metabolism*; D011770:Pyruvate Kinase / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
D000227:Adenine Nucleotides; D008345:Manganese; D011770:Pyruvate Kinase; D002262:Carboxy-Lyases; C021916:oxaloacetate decarboxylase; D019764:Phosphoenolpyruvate Carboxykinase (ATP); D008274:Magnesium