(±)-Blebbistatin

(±)-Blebbistatin is a racemic mixture of (–)-blebbistatin (Item No. 13013) and (+)-blebbistatin (Item No. 13165), the active and inactive forms, respectively. (–)-Blebbistatin is a selective cell-permeable inhibitor of non-muscle myosin II ATPases.^1,2 (–)-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 = 8 µM).³ Through these effects, (–)-blebbistatin 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.^4,5 (S)-nitro-Blebbistatin (Item No. 13891) and (R)-nitro-blebbistatin (Item No. 9001935) are more stable forms of (–)-blebbistatin and (+)-blebbistatin, respectively. The addition of a nitro group stabilizes the molecules to circumvent their degradation by prolonged blue light exposure.⁶ (S)-nitro-Blebbistatin and (R)-nitro-blebbistatin have the same stereochemistry of the active and inactive enantiomers, respectively.

WARNING This product is not for human or veterinary use.

1. 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).

2. Kovács, M., Tóth, J., Hetényi, C., et al. Mechanism of blebbistatin inhibition of myosin II. The Journal of Biological Chemisty 279(34), 35557-35563 (2004).

3. 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).

4. Kolega, J. Phototoxicity and photoinactivation of blebbistatin in UV and visible light. Biochem. Biophys. Res. Commun. 320(3), 1020-1025 (2004).

5. 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).

6. Lucas-Lopez, C., Patterson, S., Blum, T., et al. Absolute stereochemical assignment and fluorescence tuning of the small molecule tool, (−)-blebbistatin. European J. Org. Chem. 9, 1736-1740 (2005).