Construction of Mercapto-Ended Poly(Ethylene Glycol) Tethered Chain Surface for High Performance Bioconjugation
Takumi Hirase and Yukio Nagasaki. Institute of Materials Science, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba-shi, Japan
Protein chips technology has emerged as a promising tool for screening protein-protein interactions and characterizing the levels of proteins expressed in cells. Novel surface technologies must be improved to satisfy the specific protein orientation on the surface without denaturation, retaining non-fouling character of the surface. In order to construct facile immobilization of protein on the mixed PEG tethered chain on gold surface, we designed mercapto-ended PEG tethered chain surface using telechelic PEG possessing a mercapto group at both end. Marcapto-ended PEG tethered chain surface was constructed on a gold surface by the consecutive treatments with the short MeO-PEG-SH (2k), followed by the treatment with long SH-PEG-SH (5k). By changing the density of pretreated MeO-PEG-SH, the amount of modified SH-PEG-SH could be controlled. Under the suitable modification conditions, maleimide-installed protein or antibody Fab' fragment was immobilized easily on the constructed PEG surface. The constructed surface showed fairly low non-specific protein adsorption and high specific affinity, indicating that the immobilized proteins at the distal end of PEG tethered chain remained their activity. The surface possessing the mercapto-ended PEG tethered chain thus prepared can be regarded as a promising tool for protein analyzing surface.