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.

中文翻译：

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含有聚山梨酯的蛋白质制剂：是否需要金属螯合剂？


蛋白质容易在特定位点发生翻译后修饰，这会影响其理化特性，从而影响其安全性和有效性。翻译后修饰的来源包括氧和活性氧。此外，催化量的 Fe(II) 或 Cu(I) 可以促进活性氧活性的增加，从而催化特别活泼的羟基自由基的产生。当生物制药行业检测到氧化翻译后修饰时，通常的做法是在配方中添加螯合剂。然而，与金属形成的络合物可能更具破坏性。事实上，这里使用抗坏血酸氧化还原系统测定和肽图谱支持了这一点。乙二胺四乙酸 (EDTA) 的添加强烈加速了抗坏血酸铁体系中羟基自由基的形成，而二亚乙基三胺五乙酸 (DTPA) 的添加却没有。当 Fe(III) 被 Cu(II) 取代时，添加 EDTA 几乎停止了羟基自由基的产生，而添加 DTPA 则显示出继续产生，但速率降低。此外，EDTA 加速了金属催化的蛋白质氧化，因此不能保护它们免受铁介导的氧化损伤。由于每种配方都是独特的，因此添加 EDTA 或 DTPA 的理由应基于实验数据，而不是常见做法。