title: Effect of iron oxide loading on magnetoferritin structure in solution as revealed by SAXS and SANS.
abstract: Synthetic biological macromolecule of magnetoferritin containing an iron oxide core inside a protein shell (apoferritin) is prepared with different content of iron. Its structure in aqueous solution is analysed by small-angle synchrotron X-ray (SAXS) and neutron (SANS) scattering. The loading factor (LF) defined as the average number of iron atoms per protein is varied up to LF=800. With an increase of the LF, the scattering curves exhibit a relative increase in the total scattered intensity, a partial smearing and a shift of the match point in the SANS contrast variation data. The analysis shows an increase in the polydispersity of the proteins and a corresponding effective increase in the relative content of magnetic material against the protein moiety of the shell with the LF growth. At LFs above ∼150, the apoferritin shell undergoes structural changes, which is strongly indicative of the fact that the shell stability is affected by iron oxide presence.
authors.affiliation: Institute of Experimental Physics, SAS, Watsonova 47, 040 01 Kosice, Slovakia. Electronic address: melnikova@saske.sk.
authors.forename: L
authors.initials: L
authors.lastname: Melníková
authors.affiliation: Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow region, Russia; Kyiv Taras Shevchenko National University, Volodymyrska Street 64, Kyiv, 01033 Ukraine.
authors.forename: V I
authors.initials: VI
authors.lastname: Petrenko
authors.affiliation: Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow region, Russia.
authors.forename: M V
authors.initials: MV
authors.lastname: Avdeev
authors.affiliation: Helmholtz-Zentrum Geesthacht: Centre for Materials and Coastal Research, Max-Planck-Street 1, 21502 Geesthacht, Germany.
authors.forename: V M
authors.initials: VM
authors.lastname: Garamus
authors.affiliation: Wigner Research Centre for Physics, HAS, H-1525 Budapest, POB 49, Hungary.
authors.forename: L
authors.initials: L
authors.lastname: Almásy
authors.affiliation: Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow region, Russia; Kyiv Taras Shevchenko National University, Volodymyrska Street 64, Kyiv, 01033 Ukraine.
authors.forename: O I
authors.initials: OI
authors.lastname: Ivankov
authors.affiliation: Kyiv Taras Shevchenko National University, Volodymyrska Street 64, Kyiv, 01033 Ukraine.
authors.forename: L A
authors.initials: LA
authors.lastname: Bulavin
authors.affiliation: Institute of Experimental Physics, SAS, Watsonova 47, 040 01 Kosice, Slovakia.
authors.forename: Z
authors.initials: Z
authors.lastname: Mitróová
authors.affiliation: Institute of Experimental Physics, SAS, Watsonova 47, 040 01 Kosice, Slovakia.
authors.forename: P
authors.initials: P
authors.lastname: Kopčanský
mesh_terms: D001052:Apoferritins / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D033363:Neutron Diffraction; D010087:Oxides / Q000737:chemistry*; D053838:Scattering, Small Angle; D012996:Solutions
chemical_list: D005290:Ferric Compounds; D010087:Oxides; D012996:Solutions; C088922:magnetoferritin; C000499:ferric oxide; D001052:Apoferritins; D007501:Iron
keywords: Apoferritin; Biorelevant magnetic nanoparticles; Contrast variation; Magnetoferritin; Small-angle X-ray scattering; Small-angle neutron scattering