title: Encapsulated magnetic nanoparticles as supports for proteins and recyclable biocatalysts.
abstract: This paper describes the bioconjugation of histidine-tagged enzymes and other proteins to the surface of composite "magnetomicelles" consisting of magnetic gamma-Fe2O3 nanoparticles encapsulated within cross-linked polystyrene-block-polyacrylate copolymer micelle shells. Free carboxylic acid groups on the magnetomicelle surface were converted to Cu2+-iminodiacetic acid (IDA) for protein capture. The conjugation of T4 DNA ligase and enhanced green fluorescent protein to magnetomicelles revealed that proteins were captured with a high surface density and could be magnetically separated from reaction mixtures and subsequently released from the nanoparticle surface. Additionally, bioconjugation of T7 RNA polymerase yielded a functional enzyme that maintained its biological activity and could be recycled for up to three subsequent transcription reactions. We propose that protein-magnetomicelle bioconjugates are effective for protein bioseparation and enzymatic recycling and further strengthen the idea that nanoparticle surfaces have utility in protein immobilization.
authors.affiliation: University of Minnesota, Department of Chemistry, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, USA.
authors.forename: Aimee R
authors.initials: AR
authors.lastname: Herdt
authors.forename: Byeong-Su
authors.initials: BS
authors.lastname: Kim
authors.forename: T Andrew
authors.initials: TA
authors.lastname: Taton
mesh_terms: D002384:Catalysis; D003247:Conservation of Natural Resources; D011088:DNA Ligases / Q000378:metabolism; D008280:Magnetics; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011506:Proteins / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D008823:Micelles; D011506:Proteins; D011088:DNA Ligases