Thermodynamic Aspects of cAMP Dependent Protein Kinase Catalytic Subunit Allostery
2014 (English)In: The Protein Journal, ISSN 1572-3887, E-ISSN 1875-8355, Vol. 33, no 4, 386-393 p.Article in journal (Refereed) Published
Kinetics of thermal inactivation of acrylodan-labeled cAMP dependent protein kinase catalytic subunit, its binary complexes with ATP and peptide inhibitor PKI[5-24], respectively, and the ternary complex involving both of these ligands were studied at different temperatures (5-50 A degrees C). The thermodynamic parameters Delta H and Delta S for ligand binding equilibria as well as for the allosteric interaction between the binding sites of these ligands were obtained by using the Van't Hoff analysis. The results indicated that more inter- and intra-molecular non-covalent bonds were involved in ATP binding with the protein when compared to the peptide binding. Similarly, nucleotide and peptide binding steps were accompanied with different entropy effects, while almost no entropy change accompanied PKI[5-24] binding, suggesting that the protein flexibility was not affected in this case. Differently from the binary complex formation the ternary complex formation was accompanied by a significant entropy change and with intensive formation of new non-covalent interactions (Delta H). At the same time both ligand binding steps as well as the allosteric interaction between ligand binding sites could be described by a common entropy-enthalpy compensation plot, pointing to a similar mechanism of these phenomena. It was concluded that numerous weak interactions govern the allostery of cAMP dependent protein kinase catalytic subunit.
Place, publisher, year, edition, pages
2014. Vol. 33, no 4, 386-393 p.
cAMP-Dependent protein kinase catalytic subunit, Protein denaturation, Fluorescence spectroscopy, Acrylodan, Ligand binding, Protein stabilization, Thermodynamics, Allostery
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
IdentifiersURN: urn:nbn:se:uu:diva-231288DOI: 10.1007/s10930-014-9570-1ISI: 000339901900009PubMedID: 24985055OAI: oai:DiVA.org:uu-231288DiVA: diva2:744546