myosin ii

para-Nitroblebbistatin is a non-cytotoxic, non-fluorescent, photostable, and specific inhibitor of myosin II. para-Nitroblebbistatin can be used to study the specific roles of myosin II in physiology, development, and cell biology.

BTS (N-Tosylbenzylamine) is a potent inhibitor of Ca2+-stimulated myosin S1 ATPase (IC50 : 5 μM) .

(-)-Blebbistatin ((S)-(-)-Blebbistatin) is an S enantiomer of blebbistatin. It is a potent and selective myosin II inhibitor with IC50 ranging from 0.5 to 5 μM.

MLCK inhibitor peptide 18 acetate is a selective competitive inhibitor of myosin light chain kinase (IC50 = 50 nM). Displays 4000-fold selectivity over CaM kinase II and does not inhibit PKA. Cell permeable.

(+)-Blebbistatin is the inactive enantiomer of (–)-Blebbistatin. (–)-Blebbistatin is a selective myosin II ATPase inhibitor.

A-3 hydrochloride is a potent, cell-permeable, reversible, ATP-competitive non-selective antagonist of various kinases. It inhibits PKC and casein kinase I with Ki values of 47 μM and 80 μM, respectively[1], and also inhibits PKA (Ki=4.3 μM), casein kinase II (Ki=5.1 μM), and myosin light chain kinase (MLCK) (Ki=7.4 μM).

MT-110 is a selective, potent, brain-permeable non-muscle myosin II (NMII) inhibitor with an EC50 of 0.68 uM in a cytokinesis assay, >70-fold selectivity over cardiac myosin II (CMII).

Blebbistatin ((±)-Blebbistatin) is a non-muscle myosin II (NMII)-selective and non-muscle myosin heavy chain 9 (MYH9)-specific inhibitor that promotes directional migration of corneal endothelial cells (CECs) and accelerates wound healing, while preserving the integrity of cell junctions and barrier function.

(S)-nitro-Blebbistatin is a more stable form of (-)-blebbistatin , which is a selective cell-permeable inhibitor of non-muscle myosin II ATPases. (-)-Blebbistatin rapidly and reversibly inhibits Mg-ATPase activity and in vitro motility of non-muscle myosin IIA and IIB for several species (IC50s = 0.5-5 μM), while poorly inhibiting smooth muscle myosin (IC50 = 80 μM). Through these effects, it blocks apoptosis-related bleb formation, directed cell migration, and cytokinesis in vertebrate cells. However, prolonged exposure to blue light (450-490 nm) results in degradation of blebbistatin to an inactive product via cytotoxic intermediates, which may be problematic for its use in fluorescent live cell imaging applications. The addition of a nitro group stabilizes the molecule to circumvent its degradation by prolonged blue light exposure. (S)-nitro-Blebbistatin has the same stereochemistry as the active (-)-blebbistatin enantiomer.

para-amino-Blebbistatin is a more water-soluble form of (S)-4'-nitro-blebbistatin , which is a more stable and less phototoxic form of (-)-blebbistatin .1,2,3 (-)-Blebbistatin is a selective cell-permeable inhibitor of non-muscle myosin II ATPases that rapidly and reversibly inhibits Mg-ATPase activity and in vitro motility of non-muscle myosin IIA and IIB for several species (IC50s = 0.5-5 μM), while poorly inhibiting smooth muscle myosin (IC50 = 80 μM).2,3,4 Through these effects, it blocks apoptosis-related bleb formation, directed cell migration, and cytokinesis in vertebrate cells. However, prolonged exposure to blue light (450-490 nm) results in degradation of blebbistatin to an inactive product via cytotoxic intermediates, which may be problematic for its use in fluorescent live cell imaging applications.5,6 The addition of a 4'-amino group increases its water solubility, decreases the inherent fluorescence, stabilizes the molecule to circumvent its degradation by prolonged blue light exposure, and decreases its phototoxicity while retaining the in vitro and in vivo activity of blebbistatin.7 para-amino-Blebbistatin has the same stereochemistry as the active (-)-blebbistatin enantiomer. |1. Várkuti, B.H., Képiró, M., Horváth, I.á., et al. A highly soluble, non-phototoxic, non-fluorescent blebbistatin derivative. Sci. Rep. 6:26141, (2016).|2. Straight, A.F., Cheung, A., Limouze, J., et al. Dissecting temporal and spatial control of cytokinesis with a myosin II inhibitor. Science 299(5613), 1743-1747 (2003).|3. Kovács, M., Tóth, J., Hetényi, C., et al. Mechanism of blebbistatin inhibition of myosin II. J. Biol. Chem. 279(34), 35557-35563 (2004).|4. Limouze, J., Straight, A.F., Mitchison, T., et al. Specificity of blebbistatin, an inhibitor of myosin II. J. Muscle Res. Cell Motil. 25(4-5), 337-341 (2004).|5. Kolega, J. Phototoxicity and photoinactivation of blebbistatin in UV and visible light. Biochem. Biophys. Res. Commun. 320(3), 1020-1025 (2004).|6. Sakamoto, T., Limouze, J., Combs, C.A., et al. Blebbistatin, a myosin II inhibitor, is photoinactivated by blue light. Biochemistry 44(2), 584-588 (2005).|7. Verhasselt, S., Roman, B.I., Bracke, M.E., et al. Improved synthesis and comparative analysis of the tool properties of new and existing D-ring modified (S)-blebbistatin analogs. Eur. J. Med. Chem. 136, 85-103 (2017).

JB061 is a nonmuscle myosin inhibitor, demonstrating selective inhibitory activity with IC50 values of 4.4 μM (Cardiac muscle myosin), 9.1 μM (Skeletal muscle myosin), and >100 μM (Smooth muscle myosin II). It exhibits limited efficacy in reducing ATPase activity, with an IC50 exceeding 200 μM. Furthermore, JB061 displays cytotoxic effects on COS-7 cells, evidenced by an IC50 value of 39 μM.

JB062 is a chemical compound acting as a nonmuscle myosin inhibitor, exhibiting IC50 values of 1.6, 5.4, and >100 μM against skeletal muscle myosin, cardiac muscle myosin, and smooth muscle myosin II, respectively. It selectively exhibits cytotoxicity towards human cancer cells without affecting normal cells. The compound is applicable in research fields concerning muscle spasticity, chronic musculoskeletal pain, and hypertrophic cardiomyopathy.

(R)-(+)-Blebbistatin O-Benzoate is a derivative of Blebbistatin. (R)-(+)-Blebbistatin is a 1-phenyl-2-pyrrolidinone derivative and a selective inhibitor of non-muscle myosin II. It blocks cell blebbing rapidly and reversibly and also disrupts directed cell migration and cytokinesis in vertebrate cell. (R)-(+)-Blebbistatin can also inhibit contraction of the cleavage furrow without disrupting mitosis or contractile ring assembly. (R)-(+)-Blebbistatin is suitable as a negative control for (S)-(-)-Blebblastatin.

JB002, a myosin II inhibitor, exhibits potent activity with an IC50 of ≤10 μM. It holds potential for research applications in muscle spasticity, chronic musculoskeletal pain, and hypertrophic cardiomyopathy.

(S)-3'-hydroxy-Blebbistatin is a more stable and less phototoxic derivative of (–)-blebbistatin, retaining the latter's properties as a selective, cell-permeable inhibitor of non-muscle myosin II ATPases. Unlike its predecessor, (S)-3'-hydroxy-Blebbistatin exhibits reduced fluorescence, improving its utility in live cell imaging applications by diminishing degradation into cytotoxic intermediates under blue light exposure (450-490 nm). It effectively inhibits the Mg-ATPase activity and in vitro motility of non-muscle myosin IIA and IIB across various species with IC50 values ranging from 0.5-5 µM and shows minimal inhibition against smooth muscle myosin with an IC50 of 80 µM. This compound plays a critical role in preventing apoptosis-related bleb formation, directed cell migration, and cytokinesis in vertebrate cells, mirroring the active (–)-blebbistatin enantiomer in mechanism and efficacy.

(S)-3'-amino Blebbistatin, retaining the active stereochemistry of the less stable and more phototoxic (–)-blebbistatin, serves as a refined selective cell-permeable inhibitor of non-muscle myosin II ATPases. This compound efficaciously inhibits the Mg-ATPase activity and in vitro motility of non-muscle myosin IIA and IIB across several species with IC50s ranging from 0.5-5 µM, and exhibits minimal inhibition against smooth muscle myosin (IC50= 80 µM). Its primary functions include obstructing apoptosis-related bleb formation, directed cell migration, and cytokinesis in vertebrate cells. (S)-3'-amino Blebbistatin overcomes (–)-blebbistatin's limitation of rapid degradation under blue light (450-490 nm) exposure, which generates cytotoxic intermediates, thus posing a challenge for fluorescent live cell imaging applications. The introduction of a 3'-amino group to its structure notably reduces fluorescence while maintaining (–)-blebbistatin's activity, making it a superior alternative for research purposes.

Cucurbitacin I, cytotoxic triterpenoid sterols isolated from plants, elicits the formation of actin phospho-myosin II co-aggregates by stimulation of the RhoA ROCK pathway and inhibition of LIM-Kinase.

Selective competitive inhibitor of myosin light chain kinase (IC50 = 50 nM). Displays 4000-fold selectivity over CaM kinase II and does not inhibit PKA. Cell permeable.