Interaction of Non-Phosphorylated Liver Pyruvate Kinase with Fructose 1,6-Bisphosphate and Peptides that Mimic the Phosphorylatable N-terminus of the Enzyme

Title:Interaction of Non-Phosphorylated Liver Pyruvate Kinase with Fructose 1,6-Bisphosphate and Peptides that Mimic the Phosphorylatable N-terminus of the Enzyme

Volume: 20 Issue: 11

Author(s): Ilona Faustova and Jaak Järv

Affiliation:

Keywords: Allosteric effector, fructose 1, 6-bisphosphate, L-type pyruvate kinase, N-terminal domain, peptide, phosphoenolpyruvate.

Abstract: The interaction of non-phosphorylated L-type pyruvate kinase (L-PK) with fructose 1,6-bisphosphate (FBP), which is an allosteric activator of the phosphorylated enzyme, and peptides that mimic the phosphorylatable N-terminal regulatory domain of the enzyme, was studied. It was found that the catalytic activity of the enzyme was not enhanced in the presence of FBP, and this ligand acted as a relatively weak reversible inhibitor of the enzyme activity in the micromolar concentration range. The phosphorylation site analogue peptides RRASVA and RRAAVA had no effect on the activity of the enzyme, while the phosphorylated peptide RRAS(Pi)VA reversibly inhibited the enzyme and this process was characterised by the K_i value 47 μM. As the phosphorylated form of L-PK is a subject of significant allosteric regulation by FBP, it was concluded that phosphorylation should function as a molecular switch of the allosteric properties of this enzyme.

Cite this article as:

Faustova Ilona and Järv Jaak, Interaction of Non-Phosphorylated Liver Pyruvate Kinase with Fructose 1,6-Bisphosphate and Peptides that Mimic the Phosphorylatable N-terminus of the Enzyme, Protein & Peptide Letters 2013; 20 (11) . https://dx.doi.org/10.2174/09298665113209990008