Title
Facile Method of Protein PEGylation by a Mono-Ion Complex
Author
Shoichiro Asayama, Kana Nagashima, Hiroyoshi Kawakami
Year
2017
Journal
ACS Omega
Abstract
Diethylaminoethyl end-modified poly(ethylene glycol) (DEAE-PEG) has been synthesized for the noncovalent PEGylation of proteins. The resulting DEAE-PEG and catalase formed an ion complex, that is, a protein mono-ion complex (MIC). The formation of the protein MIC was confirmed by native poly(acrylamide) gel electrophoresis and gel-filtration chromatography. The resulting catalase MIC preserved the catalase activity, confirmed by monitoring the O2concentration with a Clark-type oxygen electrode, in spite of MIC formation. The catalase activity of the protein MIC was protected in the presence of a protease, trypsin, or 10% fetal bovine serum. Furthermore, less change in the circular dichroism measurements of the catalase MIC was observed as compared to those of a catalase–PEG conjugate (covalent PEGylation), suggesting less influence of the protein conformation. Consequently, the formation of the MIC is considered to be a facile method of protein PEGylation.
Full Article
Instrument
J-820
Keywords
Circular dichroism, Secondary structure, Tertiary structure, Chemical stability, Materials, Biochemistry