title: Smart PEGylation of trypsin.
abstract: Thermoresponsive oligo(ethylene glycol)-based copolymers were investigated for trypsin conjugation. These copolymers have been synthesized by atom transfer radical polymerization of 2-(2-methoxyethoxy)ethyl methacrylate (MEO(2)MA) with oligo(ethylene glycol) methyl ether methacrylate (OEGMA(475), M(n) = 475 g.mol(-1)) at 60 degrees C in the presence of copper(I) chloride and 2,2'-bipyridyl. Two different ATRP initiators, containing succinimidyl ester moieties, were tested, namely, N-succinimidyl-2-bromopropionate and N-succinimidyl-2-bromoisobutyrate. In both cases, ATRP afforded well-defined polymers with a narrow molecular weight distribution and controlled chain-ends. However, the efficiency of initiation of the two initiators was lower than 1 and therefore the formed polymers exhibited a higher than expected mean degree of polymerization. Nevertheless, all types of polymers could be conjugated to trypsin. The conjugation reaction was performed in borax-HCl buffer. Sodium dodecyl sulfate poly(acrylamide) gel electrophoresis (SDS-PAGE) indicated that polymer/enzyme conjugates were obtained in all cases. However, (co)polymers initiated by N-succinimidyl-2-bromopropionate led to the best conjugation results. The formed P(MEO(2)MA-co-OEGMA(475))-trypsin conjugates were found to be thermoresponsive and moreover exhibited a higher enzymatic activity than unmodified trypsin.
authors.affiliation: Research Group Nanotechnology for Life Science, Fraunhofer Institute for Applied Polymer Research, Geiselbergstrasse 69, Potsdam-Golm 14476, Germany.
authors.forename: Zoya
authors.initials: Z
authors.lastname: Zarafshani
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Obata
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Lutz
mesh_terms: D004591:Electrophoresis, Polyacrylamide Gel; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008970:Molecular Weight; D009391:Nephelometry and Turbidimetry; D011092:Polyethylene Glycols / Q000737:chemistry*; D014357:Trypsin / Q000737:chemistry*
chemical_list: D011092:Polyethylene Glycols; D014357:Trypsin