Use of polymer conjugates for the intraperoxisomal delivery of engineered human alanine: glyoxylate aminotransferase as a protein therapy for primary hyperoxaluria type I

Autores de CIPF

• Marina Talelli

  Autor

• 

  Maria Jesus Vicent Docon

  Autor

Participantes ajenos a CIPF

• Roncador, A
• Oppici, E
• Pariente, AN
• Donini, M
• Dusi, S
• Voltattorni, CB
• Cellini, B

Grupos de Investigación

• Laboratorio de Polímeros Terapéuticos

  

  Jefe/a de Grupo

  Maria Jesus Vicent Docon

Abstract

Alanine: glyoxylate aminotransferase (AGT) is a liver peroxisomal enzyme whose deficit causes the rare disorder Primary Hyperoxaluria Type I (PH1). We now describe the conjugation of poly(ethylene glycol)-co-poly(L-glutamic acid) (PEG-PGA) block-co-polymer to AGT via the formation of disulfide bonds between the polymer and solvent-exposed cysteine residues of the enzyme. PEG-PGAconjugation did not affect AGT structural/functional properties and allowed the enzyme to be internalized in a cellular model of PH1 and to restore glyoxylate-detoxification. The insertion of the C387S/K390S amino acid substitutions, known to favor interaction with the peroxisomal import machinery, reduced conjugation efficiency, but endowed conjugates with the ability to reach the peroxisomal compartment. These results, along with the finding that conjugates are hemocompatible, stable in plasma, and non-immunogenic, hold promise for the development of polypeptide-based AGT conjugates as a therapeutic option for PH1 patients and represent the base for applications to other diseases related to deficits in peroxisomal proteins. (C) 2016 Elsevier Inc. All rights reserved.

Keywords

• Protein therapeutics; Polymer conjugates; Primary hyperoxaluria; Rare disease; Peroxisomal targeting; Enzyme administration