title: Heterogeneities in ferritin dimers as characterized by gel filtration, nuclear magnetic resonance, electrophoresis, transmission electron microscopy, and gene engineering techniques.
abstract: To understand the mechanism underlying the preferential dimerization of ferritin shells, we studied monomers and dimers from both horse spleen and recombinant horse L-apoferritin by using gel filtration, nuclear magnetic resonance, electrophoresis, transmission electron microscopy, and gene engineering techniques. Our study of the kinetics of dimer-monomer dissociation that is produced by heating revealed the presence of at least two types of dimers, namely, weakly and strongly linked dimers with activation energies of 124 +/- 14 and 157 +/- 16 kJ/mol, respectively. Our study using thiol reagents indicated that the dimerization in horse spleen ferritin is partially mediated by disulfide bridges being formed between H-chains. Our analysis of the components that resulted from the dimer-monomer dissociation further clarified that these dimers form interdigitation structures. In summary, five types of dimers were identified in horse spleen apoferritin: reversible dimers with very weak interaction, non-sulfide dimers with weak interaction, non-sulfide dimers with strong interaction, disulfide dimers linked only by disulfide bridges, and disulfide dimers linked by disulfide bridges and having other interactions.
authors.affiliation: Nagayama Protein Array Project, ERATO, JRDC Tsukuba Research Consortium, Ibaraki, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Yang
authors.forename: K
authors.initials: K
authors.lastname: Matsubara
authors.forename: M
authors.initials: M
authors.lastname: Yamaki
authors.forename: S
authors.initials: S
authors.lastname: Ebina
authors.forename: K
authors.initials: K
authors.lastname: Nagayama
mesh_terms: D000818:Animals; D001052:Apoferritins / Q000737:chemistry / Q000302:isolation & purification; D002850:Chromatography, Gel; D004220:Disulfides / Q000737:chemistry; D004586:Electrophoresis; D005293:Ferritins / Q000737:chemistry*; D005821:Genetic Techniques; D006736:Horses; D006358:Hot Temperature; D009682:Magnetic Resonance Spectroscopy; D008854:Microscopy, Electron; D011994:Recombinant Proteins / Q000737:chemistry; D013154:Spleen / Q000737:chemistry
chemical_list: D004220:Disulfides; D011994:Recombinant Proteins; D005293:Ferritins; D001052:Apoferritins