(-)-Blebbistatin is a cell-permeable non-muscle myosin II ATPases inhibitor with an IC50 range of 2 μM [1,2].

Non-muscle myosin II (NM II), an actin-binding protein, plays a central role in regulation of cell migration, adhesion and differentiation [4]. Recent insight into the importance of NM II in these processes has been highlighted by genetic deletion and mutation methods that discovered NM II mutations affect the function of a wide range of proteins and cause monogenic diseases [5.6].

(-)-Blebbistatin is a small molecule inhibitor and preferentially binds to the myosin-ADP-Pi complex to slow down phosphate release [2]. The inhibitor completely eliminate contraction of activity of actin-activated Mg-ATPase and motility of myosins II for several species in vitro (IC50 = 0.5-5.0 μM) [8,9], but it has poor effects on smooth muscle myosin II (IC50 =80 μM) and myosins I,V, and X [3]. Furthermore, blebbistatin can potently inhibit mammalian arterial smooth muscle (IC50=5 μM) [9]. The property that blebbistatin blocks myosin II in an actin-detached state and prevents rigid actomyosin cross-linking is a great advantage in vivo applications [2,11].

In a constant-pressure grant perfusion model system, the CB and TM cells were treated with blebbistatin (10-200 M) and cell morphology was changed, and actin stress fiber content decreased. The blebbistatin effect was completely reversible by washout within 24 hours [10]. Blebbistatin inhibited single cellular contraction without altering the morphologies of intracellular calcium transients (IC50 = 0.43 μM). Exposure to UV light at wavelengths below 488 nm can also cause blebbistatin rapidly suppressed. [8].

References:
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