Binding Constant Determination Studies Utilizing Recombinant ΔCREB Protein

摘要

ABSTRACTIn this study, we report the binding constants (Kd) of the cAMP-responsive element binding protein (ΔCREB) for various cAMP-response element (CRE) motifs. We utilized purified recombinant ΔCREB protein in binding reactions with natural CRE motifs found in the promoter of two neuropeptide hormone genes and with several variant CRE motifs. TheKdof ΔCREB for the perfectly palindromic CRE, TGACGTCA, found within the somatostatin promoter is estimated to be 5.0 × 10−9M. TheKdof ΔCREB for the variant CRE motif TG_CGTCA found within the enkephalin promoter is calculated to be in the 3 × 10−8M. These studies provide anin vitroquantitative assessment of the binding affinity of ΔCREB for various