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).
Rp-8-bromo-Cyclic AMPS (Rp-8-bromo-cAMPS) is a cell-permeable cAMP analog that combines an exocyclic sulfur substitution in the equatorial position of the cyclophosphate ring with a bromine substitution in the adenine base of cAMP. It acts as an antagonist of cAMP-dependent protein kinases (PKAs) and is resistant to hydrolysis by cyclic nucleotide phosphodiesterases. Rp-8-bromo-cAMPS more effectively antagonizes cAMP-dependent activation of purified PKA type I from rabbit muscle than PKA type II from bovine heart.
Rp-8-CPT-cAMP is a structural combination of the lipophilic and non-hydrolyzable cAMP analogs, 8-CPT-cyclic AMP and Rp-cyclic AMPS .[1] It functions as a site-selective inhibitor of protein kinase A (PKA) type I and II, with preference towards site A of type I and site B of type II.2 By occupying cAMP binding sites at the regulatory subunit of PKA, Rp-8-CPT-cAMP prevents the kinase holoenzyme from dissociative activation.[2],[3]
Sp-8-CPT-cAMPS is a powerful and specific cAMP analog that activates cAMP-dependent protein kinase A (PKA I and PKAII) selectively and effectively. It exhibits a 153-fold preference for site A of RI over site A of RII, and a 59-fold preference for site B of RII over site B of RI.
Rp-8-CPT-cAMPS is a powerful and competitive antagonist of cAMP-induced activation of cAMP-dependent protein kinase (PKA) I and II. Acting as a potent cAMP analog, Rp-8-CPT-cAMPS exhibits a preference for site A of RI over site A of RII. Additionally, it favors site B of RII over site B of RI. This compound effectively inhibits cAMP-dependent PKA activation and demonstrates selectivity in binding to specific sites within the protein kinase.