CP-681301，5MG，SML3512-5MG，Sigma

Biochem/physiol Actions

ATP-competitive, potent and selective inhibitor against cyclin-dependent kinase Cdk5 both in vitro and in vivo.
CP-681301 is a potent, ATP-competitive cyclin-dependent kinase Cdk5 inhibitor (Ki = 13.7 nM; 2.8-/40-fold selectivity over Cdk2/GSK-3β) that blocks Cdk5 substrates phosphorylation in cultures (tau pS235 IC50 = 513 nM in CHO p25/CDK5/tau transfectants; IC50 ~500 nM against 48-h 10 µM oligomeric Aβ42-stimulated APP pT668 in murine embryonic neurons) and reverses the upregulated tau pS235 level in Cdk5 activator p25-overexpressing transgenic neonatal mice in vivo (5.8 mg/kg s.c.; 6 hrs). CP-681301 selectively inhibits Cdk5-dependent proliferation of human medullary thyroid carcinoma (MTC), but not normal human fibroblasts in cultures (5 µM, 48 hrs).