title: Enzyme immobilization on a nanoadsorbent for improved stability against heavy metal poisoning.
abstract: Magnetic nanoparticles modified with siloxane layers bearing amino and thiol functions have been used for immobilization of urease either by adsorption or via surface grafting. The activity of the immobilized enzyme in the hydrolysis of urea extended to the levels typical of the native enzyme, while its long-term stability in combination with magnetic retraction opened for its repeated use in both analysis and detoxification of bio-fluids. The immobilized urease revealed strongly enhanced stability and 65% activity in the presence of 0.1mmol/l of Hg(2+) or 0.3mmol/l of Cu(2+) while the native urease did not retain any activity at all. The enzyme grafting was shown to be a potentially perspective tool in alleviation of heavy metal poisoning and to be providing an opportunity for use of the developed adsorbents as both biosensors and bio-reactants for removal of urea from biofluids.
authors.affiliation: Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, 17, General Naumov Street, Kyiv 03164, Ukraine.
authors.forename: R P
authors.initials: RP
authors.lastname: Pogorilyi
authors.affiliation: Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, 17, General Naumov Street, Kyiv 03164, Ukraine.
authors.forename: I V
authors.initials: IV
authors.lastname: Melnyk
authors.affiliation: Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, 17, General Naumov Street, Kyiv 03164, Ukraine. Electronic address: zub_yuriy@isc.gov.ua.
authors.forename: Y L
authors.initials: YL
authors.lastname: Zub
authors.affiliation: Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden. Electronic address: gulaim.seisenbaeva@slu.se.
authors.forename: G A
authors.initials: GA
authors.lastname: Seisenbaeva
authors.affiliation: Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden. Electronic address: vadim.kessler@slu.se.
authors.forename: V G
authors.initials: VG
authors.lastname: Kessler
mesh_terms: D000327:Adsorption; D002021:Buffers; D004800:Enzymes, Immobilized / Q000378:metabolism*; D000075322:Heavy Metal Poisoning; D006868:Hydrolysis; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011041:Poisoning / Q000628:therapy*; D012996:Solutions; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014508:Urea; D014510:Urease / Q000378:metabolism*
chemical_list: D002021:Buffers; D004800:Enzymes, Immobilized; D058185:Magnetite Nanoparticles; D012996:Solutions; D014508:Urea; D014510:Urease
keywords: Enzyme activity; Heavy metal; Magnetic nano adsorbent; Surface modification; Urea; Urease