Kinase experiment:

Assays are performed using the STK2 kinase system from Cisbio. 5 μL mixture of a 1 μM STK2 substrate and ATP (ROCK-I: 4 μM; ROCK-II: 20 μM) in STK-buffer is added to the wells. 20 nL of test compounds (SR-3677) is dispensed. Reaction is started by addition of 5 μL of 2.5 nM. ROCK-I or 0.5 nM ROCK-II in STK-buffer. After 4 h at RT the reaction is stopped by addition of 10 μL of 1x antibody and 62.5 nM Sa-XL in detection buffer[1].

SR-3677 is a novel, potent and highly selective inhibitor of Rho Kinase (ROCK-II) with the IC50 value of ~0.3nM in enzyme and cell based assays [1].

SR-3677 has been reported to selectively inhibit the ROCK- II with the IC50 values of ~3nM, ~3nM, 56nM, 3.968μM,1.190μM and 7.491μM for ROCK-II，ppMLC, ROCK-I, PKA, MRCK and Akt1, respectively. In addition, SR-3677 has been shown several key binding elements that contribute to the high potency and selectivity in the docking assay. Furthermore, SR-3677 has been revealed to be efficacious in enhancing aqueous humor outflow and in target modulation in the pharmacology studies [1].

References:
[1] Feng Y1, Yin Y, Weiser A, Griffin E, Cameron MD, Lin L, Ruiz C, Schürer SC, Inoue T, Rao PV, Schroter T, Lograsso P. Discovery of substituted 4-(pyrazol-4-yl)-phenylbenzodioxane-2-carboxamides as potent and highly selective Rho kinase (ROCK-II) inhibitors. J Med Chem. 2008 Nov 13;51(21):6642-5. doi: 10.1021/jm800986w. Epub 2008 Oct 4.