Resurfaced shape complementary proteins that selectively bind the oncoprotein gankyrin
Alex M Chapman1, Brian R McNaughton
1Department of Chemistry and ‡Department of Biochemistry & Molecular Biology, Colorado State University , Fort Collins, Colorado 80523, United States.
Abstract:
Increased cellular levels of protein-protein interactions involving the ankyrin repeat oncoprotein gankyrin are directly linked to aberrant cellular events and numerous cancers. Inhibition of these protein-protein interactions is thus an attractive therapeutic strategy. However, the relatively featureless topology of gankyrin's putative binding face and large surface areas involved in gankyrin-dependent protein-protein interactions present a dramatic challenge to small molecule discovery. The size, high folding energies, and well-defined surfaces present in many proteins overcome some of the challenges faced by small molecule discovery. We used split-superpositive Green Fluorescent Protein (split-spGFP) reassembly to screen a 5×10(9) library of resurfaced proteins that are shape complementary to the putative binding face of gankyrin and identified mutants that potently and selectively bind this oncoprotein in vitro and in living cells. Collectively, our findings represent the first synthetic proteins that bind gankyrin and may represent a general strategy for developing protein basic research tools and drug leads that bind disease-relevant ankyrin repeats.
Insights
Researchers developed novel synthetic proteins to target gankyrin, an oncoprotein linked to cancer. This breakthrough offers a new strategy for developing cancer therapies and research tools by inhibiting disease-driving protein interactions.
Area of Science:
- Biochemistry
- Molecular Biology
- Oncology
Background:
- Aberrant protein-protein interactions involving the ankyrin repeat oncoprotein gankyrin are implicated in numerous cancers.
- Targeting these interactions is a promising therapeutic strategy, but gankyrin's binding face poses challenges for traditional small molecule drug discovery due to its large, featureless surface.
Discussion:
- This study employed a split-superpositive Green Fluorescent Protein (split-spGFP) reassembly system to screen a large library of engineered proteins.
- The screening identified novel protein mutants designed to be shape-complementary to gankyrin's binding site, overcoming the limitations of small molecule approaches.
Key Insights:
- The identified synthetic proteins demonstrate potent and selective binding to gankyrin both in vitro and within living cells.
- This represents the first instance of engineered proteins successfully binding to gankyrin, validating the protein engineering approach.
Outlook:
- These findings establish a generalizable strategy for developing protein-based research tools and potential drug leads against disease-relevant ankyrin repeat proteins.
- This approach could pave the way for new therapeutic interventions targeting cancers driven by gankyrin and similar oncoproteins.
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