Pyroglutamation of cell surface proteins CD47 and TRP1 by glutaminyl cyclase modulates therapeutic antibody binding

Anneloes van der Plas-van Duijn1,2, Levi M T Winkelman3, Claire Lensen1

  • 1Department of Dermatology, Leiden University Medical Center, Leiden, the Netherlands.

Communications Biology
|November 13, 2025
PubMed

Insights

Pyroglutamation, a protein modification, impacts therapeutic antibody binding to cancer targets CD47 and TRP1. This modification affects antibody affinity and protein trafficking, highlighting its role in antibody-based cancer therapies.

Area of Science:

  • Biochemistry
  • Immunology
  • Oncology

Background:

  • Therapeutic monoclonal antibodies are crucial in cancer treatment.
  • Post-translational modifications (PTMs) like glycosylation influence antibody binding.
  • The effect of other PTMs, such as pyroglutamation, on therapeutic antibody binding is understudied.

Purpose of the Study:

  • To investigate the impact of pyroglutamation on the binding affinity of therapeutic antibodies targeting CD47 and TRP1.
  • To understand how pyroglutamation affects antibody recognition and protein localization.

Main Methods:

  • Utilized pyroglutamation as a post-translational modification.
  • Investigated binding affinity of therapeutic antibodies targeting CD47 and TRP1.
  • Analyzed the role of N-terminal glutamine and pyroglutamation in antibody recognition and cell surface trafficking.

Main Results:

  • Pyroglutamation of CD47 and TRP1 was shown to modulate the binding of anti-CD47 magrolimab and anti-TRP1 antibodies (TA99 and flanvotumab).
  • N-terminal glutamine on CD47 is essential for antibody recognition.
  • Pyroglutamation of TRP1 influences its trafficking to the cell surface.

Conclusions:

  • Pyroglutamation by glutaminyl cyclase can alter the binding affinity of therapeutic antibodies.
  • Understanding pyroglutamation's role is vital for developing effective antibody-based cancer therapies.

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