SB743921 is a kinesin spindle protein (KSP) inhibitor with Ki of 0.1 nM, almost no affinity to MKLP1, Kin2, Kif1A, Kif15, KHC, Kif4 and CENP-E.
The Ki of SB743921 for human and mouse KSP is 0.1 nM and 0.12 nM, respectively, while the Ki of SB 743921 for other kinesins including MKLP1, Kin2 is more than 70 μM. SB743921 blocks assembly of a functional mitotic spindle, thereby causing cell cycle arrest in mitosis and subsequent cell death. SB743921 has improved potency over ispinesib in both biochemical and cellular assays. |
