Type II Kinase Inhibitors Targeting Cys-Gatekeeper Kinases Display Orthogonality with Wild Type and...

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Background:

• Analogue-sensitive (AS) kinases are targeted using the 'bump-hole' method with pyrazolopyrimidine-based inhibitors.
• This method is effective for only a subset of kinases, limiting its broad applicability.
• Many kinases are intolerant to existing AS kinase inhibitor approaches.

Purpose of the Study:

• To expand the scope of analogue-sensitive (AS) kinase technology.
• To design novel type II kinase inhibitors targeting Cys-gatekeeper kinases.
• To develop inhibitors effective against the 'DFG-out' kinase conformation.

Main Methods:

• Designed and synthesized type II kinase inhibitors, ASDO2/6 (analogue-sensitive 'DFG-out' kinase inhibitors 2 and 6).
• Validated inhibitor potency and selectivity in vitro against Greatwall kinase (GWL), Aurora-A, and cyclin-dependent kinase-1.
• Tested inhibitor efficacy in cells using M110C-GWL-expressing mouse embryonic fibroblasts.

Main Results:

• ASDO2/6 demonstrated submicromolar potency against Cys-gatekeeper kinases.
• Cys-gatekeeper kinases were sensitive to ASDO2/6 but not 3MB-PP1, and vice versa for other AS kinases.
• Established differential sensitivity between ASDO2/6 and existing AS kinase inhibitors.

Conclusions:

• ASDO2/6 inhibitors effectively target Cys-gatekeeper kinases via the 'DFG-out' conformation.
• This technology expands the utility of AS kinase inhibitors for independent targeting of multiple kinases.
• Potential applications include systems-level and translational kinase research and rational drug design.