Plain and Mono-pegylated Recombinant Human Insulin Exhibit Similar Stress-Induced Aggregation Profiles

摘要: PEGylation has been suggested to improve the stability of insulin, but evidence for that is scarce. Here, we compared forced aggregation behavior insulin and mono-PEGylated insulin. Therefore, recombinant human was conjugated on lysine B29 with 5-kDa PEG. PEG-insulin purified by size-exclusion chromatography (SEC) characterized mass spectrometry (MS). Next, were subjected heating at 75 °C, metal-catalyzed oxidation, glutaraldehyde cross-linking. The products physicochemically complementary analytical methods. Mono-PEGylation confirmed SEC MS. Under each applied stress conditions, showed comparable degradation profiles. All stressed samples submicron aggregates in size range between 50 500 nm. Covalent conformational changes found both oxidized products. Insulin its PEGylated counterpart also exhibited similar characteristics when exposed heat stress, is, slightly changed secondary tertiary structures, covalent partially intact epitopes, separation chain A from B. Both glutaraldehyde-treated contained noncovalent perturbed structure, substantial loss structure. From these results, conclude does not protect against aggregation.