Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8335704 | International Journal of Biological Macromolecules | 2011 | 6 Pages |
Abstract
Insulin conjugates in which the B1Phe residue has been chemically modified often exhibit a reduced tendency to associate into hexamers due to weakened interactions between subunits. The purpose of this study was to prepare a hexamer formulation for such insulin conjugates by using Co(III) as a coordinating metal ion. PEGylated insulin in which monomethoxypoly(ethylene glycol) (mPEG, Mr 5000 or 20,000) had been site-specifically attached to B1Phe was chosen as a model conjugate. Hexamerization of mPEG-insulin upon H2O2-mediated oxidation of Co(II) was kinetically and quantitatively analysed by visible spectrometry and size-exclusion HPLC. Co(III) mPEG-insulin hexamers thus obtained were extremely stable, existing mostly as a hexameric form even at nanomolar concentrations. A remarkable increase in hydrodynamic volumes was observed for Co(III) mPEG(20k)-insulin hexamers (1600Â kDa), as well as Co(III) mPEG(5k)-insulin hexamers (300Â kDa). Our results demonstrate the potential benefits of Co(III) hexamer formulation for weakly associating insulin conjugates in the treatment of diabetes.
Keywords
IBMXSE-HPLCtmaxEC50RP-HPLCmPEGPEGylationDPBSMALDI-TOFFBSDMEM3-isobutyl-1-methylxanthineDulbecco's modified Eagle MediumSize-exclusion high-performance liquid chromatographyfetal bovine serumDulbecco's phosphate-buffered salinematrix-assisted laser desorption/ionization time of flightCobaltReversed phase high performance liquid chromatography
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Authors
Sung In Lim, Myung Hyun Jang, Dae Jin Kim, Sung Min Bae, Se Chang Kwon,