Design and characterization of a chimeric ferritin with enhanced iron loading and transverse NMR relaxation rate.
J Biol Inorg Chem
; 15(6): 957-65, 2010 Aug.
Article
em En
| MEDLINE
| ID: mdl-20401622
ABSTRACT
This paper describes the design and characterization of a novel ferritin chimera. The iron storage protein ferritin forms a paramagnetic ferrihydrite core. This biomineral, when placed in a magnetic field, can decrease the transverse NMR relaxation times (T (2) and T (2)*) of nearby mobile water protons. Ferritin nucleic acid constructs have recently been studied as "probeless" magnetic resonance imaging (MRI) reporters. Following reporter expression, ferritin sequesters endogenous iron and imparts hypointensity to T (2)- and T (2)*-weighted images in an amount proportional to the ferritin iron load. Wild-type ferritin consists of various ratios of heavy H and light L subunits, and their ratio affects ferritin's stability and iron storage capacity. We report a novel chimeric ferritin with a fixed subunit stoichiometry obtained by fusion of the L and the H subunits (L*H and H*L) using a flexible linker. We characterize these supramolecular ferritins expressed in human cells, including their iron loading characteristics, hydrodynamic size, subcellular localization, and effect on solvent water T (2) relaxation rate. Interestingly, we found that the L*H chimera exhibits a significantly enhanced iron loading ability and T (2) relaxation compared to wild-type ferritin. We suggest that the L*H chimera may be useful as a sensitive MRI reporter molecule.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Recombinantes de Fusão
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Engenharia de Proteínas
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Ressonância Magnética Nuclear Biomolecular
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Ferritinas
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Ferro
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article