生物活性 | |||
---|---|---|---|
描述 | Ras oncoproteins belong to the Ras family of small GTPases and function as molecular switches by cycling between GTP-bound active and GDP-bound inactive forms in intracellular signaling pathways controlling cell growth, differentiation, and apoptosis. Interconversion between the two forms is reciprocally catalyzed by guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Kobe0065, a novel and effective inhibitor of Ras-Raf interaction, competitively inhibits the binding of H-Ras⋅GTP to c-Raf-1 RBD with a Ki value of 46 ± 13 μM. The IC50 value of Kobe0065 for inhibiting Ras⋅GTP is around 20 μM. Kobe0065 at 20 μM efficiently inhibited the phosphorylation of MEK and ERK, downstream kinases of Raf in NIH 3T3 cells transiently expressing H-RasG12V. Kobe0065 at 50 μM almost completely abolished the accelerating effect of the distal site without apparently affecting the catalytic activity of the GEF domain itself. Kobe0065 efficiently inhibited colony formation of H-rasG12V–transformed NIH 3T3 cells in soft agar in a dose-dependent manner with IC50 value of around 0.5 μM. In a xenograft of SW480 cells in nude mice, daily oral administration of kobe0065 at the dose of 80 mg/kg caused ∼40–50% inhibition of the tumor growth. By doubling the dose to 160 mg/kg, the activity of Kobe0065 became more evident[3]. |
实验方案 | |||
---|---|---|---|
1mg | 5mg | 10mg | |
1 mM 5 mM 10 mM |
2.22mL 0.44mL 0.22mL |
11.12mL 2.22mL 1.11mL |
22.23mL 4.45mL 2.22mL |
参考文献 |
---|