Unser 10. Leibniz Plant Biochemistry Symposium am 7. und 8. Mai war ein großer Erfolg. Thematisch ging es in diesem Jahr um neue Methoden und Forschungsansätze der Naturstoffchemie. Die exzellenten Vorträge über Wirkstoffe…
Omanische Heilpflanze im Fokus der Phytochemie IPB-Wissenschaftler und Partner aus Dhofar haben jüngst die omanische Heilpflanze Terminalia dhofarica unter die phytochemische Lupe genommen. Die Pflanze ist reich an…
Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Brandt, W.; Anders, A.; Vasilets, L. A.;Predicted Alterations in Tertiary Structure of the N-Terminus of Na+/K+-ATPase α-Subunit Caused by Phosphorylation or Acidic Replacement of the PKC Phosphorylation Site Ser-23Cell Biochem. Biophys.3783-96(2002)DOI: 10.1385/CBB:37:2:083
The protein kinase C (PKC)-mediated phosphorylation of the Na+/K+-ATPase α-subunit has been shown to play an important role in regulation of the Na+/K+-ATPase activity. In the rat α1-subunit, phosphorylation occurs at Ser-23 and results in inhibition of the transport function of the Na+/K+-ATPase, which is mimicked by replacing the Ser-23 by the negatively charged glutamic acid or by aspartic acid. Using comparative molecular modeling, we investigated whether phosphorylation or acidic replacement at position 23 causes a dramatic change in the molecular electrostatic potential at position 23 as a result of insertion of a negative charge of the phosphoryl group or Glu per se, or whether, alternatively, the modification causes larger-scale conformational changes in the N-terminus of the α-subunit. The results predict a considerable conformational change of the 30-residue stretch around Ser-23 when mutated to the residues carrying a net negative charge or being phosphorylated. The structural rearrangements occur within the N-terminal helix-loop-helix motif with a set of charged residues. This motif has structural homology with one in the Ca2+-ATPase and may form a function-related structural site in the P-type ATPases. Comparative molecular modeling indicates a lengthening of the interhelical loop and an order-to-disorder transition by disrupting a helix at position 23 because of posphorylation.