Klemme JH. Unidirectional inhibition of phosphoenolpyruvate carboxykinase from Rhodospirillum rubrum by ATP.
Arch Microbiol 1976;
107:189-92. [PMID:
816325 DOI:
10.1007/bf00446838]
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Abstract
The kinetic and regulatory properties of partially purified phosphoenolpyruvate (PEP) carboxykinase (EC 4.1.1.3.2) from Rhodospirillum rubrum were studied. The enzyme was active with guanosine- and inosinephosphates and must thus be classified as GTP (ITP): oxaloacetate carboxylase (transphosphorylating.) In the direction of oxaloacetate-foramtion, the enzyme was strongly inhibited by ATP (Ki = 0.03 mM). ITP, UTP, CTP, and GTP were less inhibitory. The inhibition was competitive with respect to GDP or IDP, but not with respect to PEP. In the direction of PEP-synthesis, the enzyme was not inhibited, but rather activated by ATP.
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