Functional and Structural Characterization of Treatment-Emergent Nirmatrelvir Resistance Mutations at Low Frequencies in the Main Protease (Mpro) Reveals a Unique Evolutionary Route for SARS-CoV-2 to Gain Resistance - Summary - MDSpire

Functional and Structural Characterization of Treatment-Emergent Nirmatrelvir Resistance Mutations at Low Frequencies in the Main Protease (Mpro) Reveals a Unique Evolutionary Route for SARS-CoV-2 to Gain Resistance

  • By

  • Natalie M Deschenes

  • Jimena Pérez-Vargas

  • Zoe Zhong

  • Merrilee Thomas

  • Calem Kenward

  • Wesley A Mosimann

  • Liam J Worrall

  • Nicholas Waglechner

  • Angel XinLiu Li

  • Finlay Maguire

  • Patryk Aftanas

  • Jason R Smith

  • Jared Lim

  • Robert N Young

  • Artem Cherkasov

  • Lubna Farooqi

  • Adnan Moinuddin

  • Lina Siddiqi

  • Imaan Malik

  • Maxime Lefebvre

  • Mark Paetzel

  • Natalie C J Strynadka

  • François Jean

  • Allison McGeer

  • Robert A Kozak

  • June 3, 2025

  • 0 min

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Objective:

To identify low-frequency antiviral resistance mutations in Mpro from NIR-RIT–treated patients and analyze their enzymatic properties, inhibitor susceptibility, and structural features, highlighting their clinical significance.

Key Findings:
  • Identified 2 novel Mpro clinical variants: D48D/L58F/P132H and D48D/L67V/K90R/P132H, which may have significant implications for treatment outcomes.
  • Mutations are localized in the Mpro N-terminal domain, impacting NIR resistance without affecting Mpro activity.
  • Mutations may disrupt the substrate binding site's structure and dynamics, reducing protein stability.
Interpretation:

The study reveals a unique evolutionary pathway for SARS-CoV-2 resistance, emphasizing the clinical importance of monitoring low-frequency resistance mutations.

Limitations:
  • Limited sample size of patients with resistance mutations, which may affect the generalizability of the findings.
  • Resistance mechanisms require further exploration to understand their implications fully.
Conclusion:

Further research is essential to explore resistance mechanisms and develop specific strategies to mitigate resistance, ensuring therapeutic efficacy against SARS-CoV-2.

Original Source(s)

Functional and Structural Characterization of Treatment-Emergent Nirmatrelvir Resistance Mutations at Low Frequencies in the Main Protease (Mpro) Reveals a Unique Evolutionary Route for SARS-CoV-2 to Gain Resistance

  • by Natalie M Deschenes, Jimena Pérez-Vargas, Zoe Zhong, Merrilee Thomas, Calem Kenward, Wesley A Mosimann, Liam J Worrall, Nicholas Waglechner, Angel XinLiu Li, Finlay Maguire, Patryk Aftanas, Jason R Smith, Jared Lim, Robert N Young, Artem Cherkasov, Lubna Farooqi, Adnan Moinuddin, Lina Siddiqi, Imaan Malik, Maxime Lefebvre, Mark Paetzel, Natalie C J Strynadka, François Jean, Allison McGeer, Robert A Kozak

  • June 3, 2025

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