GlycoTAIL and FlexiTAIL as Half-Life Extension Modules for Recombinant Antibody Fragments

Molecules. 2022 May 19;27(10):3272. doi: 10.3390/molecules27103272.

Abstract

Many therapeutic proteins are small in size and are rapidly cleared from circulation. Consequently, half-life extension strategies have emerged to improve pharmacokinetic properties, including fusion or binding to long-lasting serum proteins, chemical modifications with hydrophilic polymers such as PEGylation, or, more recently, fusion to PEG mimetic polypeptides. In the present study, two different PEG mimetic approaches, the GlycoTAIL and the FlexiTAIL, were applied to increase the hydrodynamic radius of antibody fragments of different sizes and valencies, including scFv, diabody, and scFv-EHD2 fusion proteins. The GlycoTAIL and FlexiTAIL sequences of varying lengths are composed of aliphatic and hydrophilic residues, with the GlycoTAIL furthermore comprising N-glycosylation sites. All modified proteins could be produced in a mammalian expression system without reducing stability and antigen binding, and all modified proteins exhibited a prolonged half-life and increased drug disposition in mice. The strongest effects were observed for proteins comprising a FlexiTAIL of 248 residues. Thus, the GlycoTAIL and FlexiTAIL sequences represent a flexible and modular system to improve the pharmacokinetic properties of proteins.

Keywords: CEA; FAP; PEG mimetic; diabody; half-life extension; hydrodynamic radius; scFv; scFv-EHD2 fusion protein.

MeSH terms

  • Animals
  • Antibodies* / chemistry
  • Carrier Proteins
  • Half-Life
  • Immunoglobulin Fragments* / chemistry
  • Mice
  • Recombinant Fusion Proteins / chemistry

Substances

  • Antibodies
  • Carrier Proteins
  • EHD2 protein, mouse
  • Immunoglobulin Fragments
  • Recombinant Fusion Proteins

Grants and funding

This research received no external funding.