Improved molecular recognition of Carbonic Anhydrase IX by polypeptide conjugation to acetazolamide

Research output: Contribution to journalArticle

Abstract

The small molecule inhibitor acetazolamide (AZM) was conjugated to a set of designed polypeptides and the resulting conjugates were evaluated for their affinity to Human Carbonic Anhydrase II (HCA II) using surface plasmon resonance. The dissociation constant of the AZM-HCA II complex was 38. nM and that of the AZM conjugated polypeptide (4-C10L17-AZM) to HCA II was found to be 4. nM, an affinity enhancement of a factor of 10 due to polypeptide conjugation. For Human Carbonic Anhydrase IX (HCA IX) the dissociation constant of AZM was 3. nM, whereas that of the 4-C10L17-AZM conjugate was 90. pM, a 33-fold affinity enhancement. This dramatic affinity increase due to polypeptide conjugation was achieved for a small molecule ligand with an already high affinity to the target protein. This supports the concept that enhancements due to polypeptide conjugation are not limited to small molecule ligands that bind proteins in the mM to μM range but may be used also for nM ligands to provide recognition elements with dissociation constants in the pM range. Evaluations of two HCA IX constructs that do not carry the proteoglycan (PG) domain did not show significant affinity differences between AZM and the polypeptide conjugate, providing evidence that the improved binding of 4-C10L17-AZM to HCA IX emanated from interactions between the polypeptide segment and the PG domain found only in one carbonic anhydrase, HCA IX.

Details

Authors
Organisations
External organisations
  • Uppsala University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Medicinal Chemistry
  • Cell and Molecular Biology

Keywords

  • Acetazolamide, Human Carbonic Anhydrase, Recognition, Surface plasmon resonance, Tumor
Original languageEnglish
Pages (from-to)5838-5848
JournalBioorganic and Medicinal Chemistry
Volume25
Issue number20
Publication statusPublished - 2017 Oct
Publication categoryResearch
Peer-reviewedYes

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