Kinase experiment:

Kinase activity is determined in an assay volume of 40 μL in kinase buffer (50 mM Tris-HCl, pH 7.5, 0.1 mM EGTA, 1 mM 2-mercaptoethanol) containing 200 ng of pure active ERK5 and the indicated amount of inhibitor. Reaction started by adding 10 mM magnesium acetate, and 50 μM [γ-32P]-ATP (500 cpm/pmol) and 250 μM PIMtide (ARKKRRHPSGPPTA) as substrates. Assays are carried out for 20 min at 30℃, terminated by applying the reaction mixture onto p81 paper and the incorporated radioactivity measured[1].

ERK5-IN-1 is a potent ERK5 inhibitor with an IC50 of 87±7 nM. ERK5-IN-1 also inhibits LRRK2[G2019S] with an IC50 of 26 nM.

ERK5-IN-1 (Compound 5) exhibits a cellular EC50 for inhibiting epidermal growth factor (EGF) induced ERK5 autophosphorylation of 0.19±0.04 μM[1].

[1]. Deng X, et al. Structural determinants for ERK5 (MAPK7) and leucine rich repeat kinase 2 activities of benzo[e]pyrimido-[5,4-b]diazepine-6(11H)-ones. Eur J Med Chem. 2013;70:758-767.