Abstract: This invention relates to fluorescent probes for identification of compounds binding to protein kinases, for measurement of the affinity of inhibitors of protein kinases, and determination of the active concentration of protein kinases binding to the probe. Bisubstrate-analog character of the probe enables the simultaneous evaluation of inhibitors targeted to both ATP binding site and/or substrate protein/peptide binding domain of the kinase. High affinity of the probe (Kd=1.0 nM towards cAMP-dependent protein kinase) affords the application of the enzymes at low concentration which leads to the substantial decrease of the consumption of the kinase. Due to the ability of the conjugates of oligo(D-arginine) with a ATP binding site targeted inhibitors of this invention to bind with high affinity to a wide spectrum of (basophilic) kinases, a single Fluorescent probe is applicable for assessment of inhibitory potency of compounds towards a great number of protein kinases.

Abstract: This invention relates to fluorescent probes for identification of compounds binding to protein kinases, for measurement of the affinity of inhibitors of protein kinases, and determination of the active concentration of protein kinases binding to the probe. Bisubstrate-analog character of the probe enables the simultaneous evaluation of inhibitors targeted to both ATP binding site and/or substrate protein/peptide binding domain of the kinase. High affinity of the probe (Kd=1.0 nM towards cAMP-dependent protein kinase) affords the application of the enzymes at low concentration which leads to the substantial decrease of the consumption of the kinase. Due to the ability of the conjugates of oligo(D-arginine) with a ATP binding site targeted inhibitors of this invention to bind with high affinity to a wide spectrum of (basophilic) kinases, a single Fluorescent probe is applicable for assessment of inhibitory potency of compounds towards a great number of protein kinases.