are metal chelators needed at all?
Ema Valentina Brovč (Author), Stane Pajk (Author), Roman Šink (Author), Janez Mravljak (Author)

Abstract

Proteins are prone to post-translational modifications at specific sites, which can affect their physicochemical properties, and consequently also their safety and efficacy. Sources of post-translational modifications include oxygen and reactive oxygen species. Additionally, catalytic amounts of Fe(II) or Cu(I) can promote increased activities of reactive oxygen species, and thus catalyse the production of particularly reactive hydroxyl radicals. When oxidative post-translational modifications are detected in the biopharmaceutical industry, it is common practice to add chelators to the formulation. However, the resultant complexes with metals can be even more damaging. Indeed, this is supported here using an ascorbate redox system assay and peptide mapping. Ethylenediaminetetraacetic acid (EDTA) addition strongly accelerated the formation of hydroxyl radicals in an iron-ascorbate system, while diethylenetriaminepentaacetic acid (DTPA) addition did not. When Fe(III) was substituted with Cu(II), EDTA addition almost stopped hydroxyl radical production, whereas DTPA addition showed continued production, but at a reduced rate. Further, EDTA accelerated metal-catalysed oxidation of proteins, and thus did not protect them from Fe-mediated oxidative damage. As every formulation is unique, justification for EDTA or DTPA addition should be based on experimental data and not common practice.

Keywords

proteins;oxidation;Fenton reaction;free radicals;chelating agents;polysorbates;

Data

Language: English
Year of publishing:
Typology: 1.01 - Original Scientific Article
Organization: UL FFA - Faculty of Pharmacy
UDC: 615.4:54:547.466
COBISS: 16128003 Link will open in a new window
ISSN: 2076-3921
Views: 175
Downloads: 47
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: Slovenian
Secondary keywords: beljakovine;oksidativnost;prosti radikali;polisorbati;Farmacevtska kemija;Aminokisline;
Type (COBISS): Article
Pages: str. 1-13
Volume: ǂVol. ǂ9
Issue: ǂIss. ǂ5
Chronology: 2020
DOI: 10.3390/antiox9050441
ID: 14075136