ca2+/calmodulin-dependent kinase type ii

K-252a is a staurosporine analog isolated from Nocardiopsis sp. soil fungi. K-252a inhibits protein kinase (IC50: 470 nM, 140 nM, 270 nM, and 1.7 nM for PKC, PKA, Ca2+ calmodulin-dependent kinase type II, and phosphorylase kinase, respectively).

Two Rho-associated kinases (ROCK), ROCK-I and ROCK-II, act downstream of the G protein Rho to regulate cytoskeletal stability. The ROCKs play important roles in diverse cellular functions including cell adhesion and proliferation, smooth muscle contraction, and stem cell renewal. Glycyl-H-1152 is a selective and potent ROCK inhibitor (IC50 = 11.8 nM for ROCK-II). It is a glycylated isoquinoline compound derived from the therapeutically-important ROCK inhibitor HA-1077 (Fasudil) and exhibits better specificity. Thus, it poorly inhibits Ca2+/calmodulin-dependent kinase type II, protein kinase (PK) G, and Aurora A (IC50 = 2.57, 2.35, and 3.26 μM, respectively) as well as PKA or PKC (IC50 ≥ 10 μM for each). The potency of Glycyl-H-1152 is superior to that of other ROCK inhibitors, including Y-27632 (Ki = 220 nM) and HA-1077 (IC50 = 158 nM).