Jabalquinto A M, Laivenieks M, Zeikus J G, Cardemil E
Departamento de Ciencias Químicas, Facultad de Química y Biología, Universidad de Santiago de Chile.
J Protein Chem. 1999 Aug;18(6):659-64. doi: 10.1023/a:1020602222808.
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.
已对磷酸烯醇式丙酮酸羧激酶（PEPCKs）的ATP依赖型的两个成员（酿酒酵母和产琥珀酸厌氧螺菌）的草酰乙酸（OAA）脱羧酶和丙酮酸激酶样活性进行了比较研究。丙酮酸激酶样活性依赖于Mn2+的存在；在相同浓度下，Mg2+无效。这两种金属离子的组合可协同激活这些活性。产琥珀酸厌氧螺菌和酿酒酵母PEPCKs中这些活性的Vmax分别为主反应的0.13%和1.2%。OAA脱羧酶活性不依赖核苷酸，并且按有效性递减顺序，这些活性由Mn2+和Mg2+支持。AMP是这些反应的激活剂。产琥珀酸厌氧螺菌和酿酒酵母PEPCKs中OAA脱羧酶活性的Vmax分别为PEP形成反应的4%和0.2%。
