Beyond KRAS(G12C): Biochemical and Computational Characterization of Sotorasib and Adagrasib Binding Specificity and the Critical Role of H95 and Y96
: Mahran, Randa; Kapp, Jonas N.; Valtonen, Salla; Champagne, Allison; Ning, Jinying; Gillette, William; Stephen, Andrew G.; Hao, Feng; Pluckthun, Andreas; Härmä, Harri; Pantsar, Tatu; Kopra, Kari
Publisher: AMER CHEMICAL SOC
: WASHINGTON
: 2024
: ACS Chemical Biology
: ACS CHEMICAL BIOLOGY
: ACS CHEM BIOL
: 19
: 10
: 2152
: 2164
: 13
: 1554-8929
: 1554-8937
DOI: https://doi.org/10.1021/acschembio.4c00315
: https://doi.org/10.1021/acschembio.4c00315
Mutated KRAS proteins are frequently expressed in some of the most lethal human cancers and thus have been a target of intensive drug discovery efforts for decades. Lately, KRAS(G12C) switch-II pocket (SII-P)-targeting covalent small molecule inhibitors have finally reached clinical practice. Sotorasib (AMG-510) was the first FDA-approved covalent inhibitor to treat KRAS(G12C)-positive nonsmall cell lung cancer (NSCLC), followed soon by adagrasib (MRTX849). Both drugs target the GDP-bound state of KRAS(G12C), exploiting the strong nucleophilicity of acquired cysteine. Here, we evaluate the similarities and differences between sotorasib and adagrasib in their RAS SII-P binding by applying biochemical, cellular, and computational methods. Exact knowledge of SII-P engagement can enable targeting this site by reversible inhibitors for KRAS mutants beyond G12C. We show that adagrasib is strictly KRAS- but not KRAS(G12C)-specific due to its strong and unreplaceable interaction with H95. Unlike adagrasib, sotorasib is less dependent on H95 for its binding, making it a RAS isoform-agnostic compound, having a similar functionality also with NRAS and HRAS G12C mutants. Our results emphasize the accessibility of SII-P beyond oncogenic G12C and aid in understanding the molecular mechanism behind the clinically observed drug resistance, associated especially with secondary mutations on KRAS H95 and Y96.
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This work was supported by Academy of Finland (323433/K.K., 329012/K.K., and 353324/K.K.) and Krebsliga Schweiz grants (KFS-4147-02-2017 and KFS-5290-02-2021-R to A.P.). This project was funded in part with federal funds from the National Cancer Institute, National Institutes of Health Contract HHSN261200800001E. The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services, and the mention of trade names, commercial products, or organizations does not imply endorsement by the US government. The authors would like to thank Matt Drew, Peter Frank, Phuong Vi Le, Randy Gapud, Jose Sanchez Hernandez, Jennifer Mehalko, Shelley Perkins, Nitya Ramakrishnan, Mukul Sherekar, Kelly Snead, Simon Messing, Troy Taylor, Vanessa Wall, and Tim Waybright from the Frederick National Laboratory for Cancer Research, Frederick MD, USA for cloning, expression, purification, and QC of the used small GTPase proteins. The authors wish to acknowledge CSC-IT Center for Science, Finland, for computational resources. The authors gratefully acknowledge the Functional Genomics Center Zurich (FGCZ) of University of Zurich and ETH Zurich, and in particular Serge Chesnov, for the support on Proteomics analyses.
