Biophysical analysis of the dynamics of calmodulin interactions with neurogranin and Ca2+/calmodulin‐dependent kinase II

• DOI: 10.1002/jmr.2621
• Publication Date: 2017-04-27T22:05:19Z
• Authors: Christian Seeger; Vladimir O. Talibov; U. Helena Danielson
• Keywords: Microscale Thermophoresis; Neurogranin; Receptor–ligand kinetics

Abstract Calmodulin (CaM) functions depend on interactions with CaM‐binding proteins, regulated by . Induced structural changes influence the affinity, kinetics, and specificities of interactions. The dynamics CaM neurogranin (Ng) region /calmodulin‐dependent kinase II (CaMKII 290−309 ) have been studied using biophysical methods. These proteins opposite dependencies for binding. Surface plasmon resonance biosensor analysis confirmed that interact very rapidly, moderate affinity ( ). Calmodulin‐CaMKII were only detected in presence , exhibiting fast kinetics nanomolar CaM–Ng interaction had higher under ‐depleted k −1 = 1.6 × 10 s than ‐saturated conditions IQ motif Ng (Ng 27−50 similar as ), but no was seen conditions. Microscale thermophoresis fluorescently labeled surface results qualitatively, estimated lower affinities CaMKII Although showed expected characteristics, they may be different full‐length CaMKII. data Ng, not agree current model regulation /CaM signaling.