PEGylation of deuterohaemin–alanine–histidine–threonine–valine–glutamic acid–lysine and its influence on activity,stability, and aggregation |
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Authors: | Hang Lin Yapeng Li Hang Zhou Liping Wang Hong Cao Jun Tang Wei Li |
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Affiliation: | 1. College of Chemistry, Jilin University, Changchun 130012, People's Republic of China;2. College of Life Science, Jilin University Changchun 130012, People's Republic of China;3. Department of General Surgery, Second Hospital of Jilin University, Changchun 130041, People's Republic of China |
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Abstract: | Deuterohaemin–alanine–histidine–threonine–valine–glutamic acid–lysine (DhHP‐6) is a synthetic heme‐containing peroxidase mimic that exhibits a high peroxidase enzyme activity. Compared to other microperoxidases, DhHP‐6 has a poor stability and tends to aggregate in aqueous solutions. In this study, poly(ethylene glycol) (PEG) was used to improve the properties of DhHP‐6. Factors that affected the PEGylation product yield were investigated. PEGylated DhHP‐6 (mPEG–DhHP‐6) was characterized by reversed‐phase high‐pressure liquid chromatography (RP‐HPLC), matrix‐assisted laser desorption/ionization time of flight mass spectra (MALDI‐TOF‐MS), and ultraviolet–visible (UV–vis) spectroscopy. The results show that the optimal PEGylation reaction conditions were achieved when the PEGylation was conducted in a borate buffer solution at pH 8.0 and 25°C for 4 h with a feeding ratio of 2 equiv of active PEG. After PEGylation, mPEG–DhHP‐6 showed a great improvement in its stability with little activity loss. The UV–vis spectra of DhHP‐6 and mPEG–DhHP‐6 in different pH solutions showed that the aggregation of DhHP‐6 was partly suppressed after PEGylation. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 |
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Keywords: | biomaterials peptides UV– vis spectroscopy |
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