title: Use of polymer conjugates for the intraperoxisomal delivery of engineered human alanine:glyoxylate aminotransferase as a protein therapy for primary hyperoxaluria type I.
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-PGA conjugation 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.
authors.affiliation: Neuroscience, Biomedicine and Movement Sciences Department, Section of Biological Chemistry, University of Verona, Verona (VR), Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Roncador
authors.affiliation: Neuroscience, Biomedicine and Movement Sciences Department, Section of Biological Chemistry, University of Verona, Verona (VR), Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Oppici
authors.affiliation: Polymer Therapeutics Lab, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain.
authors.forename: Marina
authors.initials: M
authors.lastname: Talelli
authors.affiliation: Polymer Therapeutics Lab, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain.
authors.forename: Amaya Niño
authors.initials: AN
authors.lastname: Pariente
authors.affiliation: Department of Medicine, Section of General Pathology, University of Verona, Verona (VR), Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Donini
authors.affiliation: Department of Medicine, Section of General Pathology, University of Verona, Verona (VR), Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Dusi
authors.affiliation: Neuroscience, Biomedicine and Movement Sciences Department, Section of Biological Chemistry, University of Verona, Verona (VR), Italy.
authors.forename: Carla Borri
authors.initials: CB
authors.lastname: Voltattorni
authors.affiliation: Polymer Therapeutics Lab, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain. Electronic address: mjvicent@cipf.es.
authors.forename: María J
authors.initials: MJ
authors.lastname: Vicent
authors.affiliation: Neuroscience, Biomedicine and Movement Sciences Department, Section of Biological Chemistry, University of Verona, Verona (VR), Italy. Electronic address: barbara.cellini@univr.it.
authors.forename: Barbara
authors.initials: B
authors.lastname: Cellini
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D016466:CHO Cells; D003412:Cricetulus; D016503:Drug Delivery Systems; D057487:Enzyme Therapy; D006038:Glyoxylates / Q000378:metabolism; D006801:Humans; D006960:Hyperoxaluria, Primary / Q000188:drug therapy* / Q000201:enzymology / Q000378:metabolism; D008958:Models, Molecular; D020675:Peroxisomes / Q000187:drug effects / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011099:Polyglutamic Acid / Q000031:analogs & derivatives*; D000637:Transaminases / Q000008:administration & dosage* / Q000737:chemistry* / Q000235:genetics / Q000493:pharmacokinetics
chemical_list: D006038:Glyoxylates; D011099:Polyglutamic Acid; D011092:Polyethylene Glycols; D000637:Transaminases; C019635:Alanine-glyoxylate transaminase; C031150:glyoxylic acid
keywords: Enzyme administration; Peroxisomal targeting; Polymer conjugates; Primary hyperoxaluria; Protein therapeutics; Rare disease