(-)-Blebbistatin (-)-Blebbistatin ((S)-(-)-Blebbistatin) is a cell-permeable inhibitor for non muscle myosin II ATPase with IC50 of ~2 μM in cell-free assays, does not inhibit myosin light chain kinase, inhibits contraction of the cleavage furrow withou In vitro
Blebbistatin, inhibits cytokinesis, alters the smooth movement of fish keratocytes and inhibits the spontaneous blebbing of a cell line lacking filamin. Blebbistatin is shown to inhibit the enzymatic activities of HMM fragments of nonmuscle myosin IIA, nonmuscle myosin IIB and of rabbit skeletal muscle myosin S1, but not smooth muscle myosin Blebbistatin rapidly and reversibly inhibits Mg-ATPase activity and in vitro motility of non-muscle myosin IIA and IIB for several species, while poorly inhibiting smooth muscle myosin (IC50 = 80 μM). Blebbistatin potently inhibits Dictyostelium myosin II, but poorly inhibits Acanthamoeba myosin II. Blebbistatin does not inhibit representative myosin superfamily members from classes I, V, and X. Blebbistatin does not compete with nucleotide binding to the skeletal muscle myosin subfragment-1. The inhibitor preferentially binds to the ATPase intermediate with ADP and phosphate bound at the active site, and it slows down phosphate release. Blebbistatin interferes neither with binding of myosin to actin nor with ATP-induced actomyosin dissociation. Instead, it blocks the myosin heads in a products complex with low actin affinity.
In vivo
Cell Data
cell lines:Dexamethasone-sensitive (MM.1S) and -resistant (MM.1R) human MM cell lines, RPMI8226 and U266 cell lines