Differences in electrophoretic behavior between linear and branched PEG‐conjugated proteins |
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| Authors: | Eun Ji Park Myung Sun Kim Hye Suk Lee Kang Choon Lee Dong Hee Na |
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| Affiliation: | 1. College of Pharmacy and Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu, Republic of Korea;2. College of Pharmacy, The Catholic University of Korea, Bucheon, Republic of Korea;3. Drug Targeting Laboratory, College of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea |
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| Abstract: | The objective of this study was to characterize the differences in electrophoretic behavior between linear and branched PEG‐conjugated proteins. Human growth hormone and alpha‐lactalbumin modified by linear or branched PEGs with molecular weight of 10 kDa were analyzed by SEC, MALDI‐TOF MS, SDS‐PAGE, and microchip CGE (MCGE). Chromatographic and mass spectrometric differences between the linear and branched PEG‐proteins on SEC and MALDI‐TOF MS were small, but their electrophoretic behaviors on SDS‐PAGE and MCGE were significantly different. In particular, MCGE showed significant differences in the peak width and the migration times of linear and branched PEG‐proteins, in which the branched PEG‐proteins exhibited a narrower peak and longer migration time than the linear PEG‐proteins. This phenomenon may explain the longer circulation half‐life for the branched PEG‐proteins observed in previously reported in vivo studies. Consequently, this study indicates that MCGE may be a valuable tool for differentiating linear and branched PEG‐proteins. |
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| Keywords: | Branched PEG Microchip CGE PEG‐protein conjugates PEGylation |
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