The rate of Fe(3+) release from horse spleen ferritin (HoSF) was measured using the Fe(3+)-specific chelator desferoxamine (DES). The reaction consists of two kinetic phases. The first is a rapid non-linear reaction followed by a slower linear reaction. The overall two-phase reaction was resolved into three kinetic events: 1) a rapid first-order reaction in HoSF (k(1)); 2) a second slower first-order reaction in HoSF (k(2)); and 3) a zero-order slow reaction in HoSF (k(3)). The zero-order reaction was independent of DES concentration. The two first-order reactions had a near zero-order dependence on DES concentration and were independent of pH from 6.8 to 8.2. The two first-order reactions accounted for 6-9 rapidly reacting Fe(3+) ions. Activation energies of 10.5±0.8, 13.5±2.0 and 62.4±2.1kJ/mol were calculated for the kinetic events associated with k(1), k(2), and k(3), respectively. Iron release occurs by: 1) a slow zero-order rate-limiting reaction governed by k(3) and corresponding to the dissociation of Fe(3+) ions from the FeOOH core that bind to an Fe(3+) binding site designated as site 1 (proposed to be within the 3-fold channel); 2) transfer of Fe(3+) from site 1 to site 2 (a second binding site in the 3-fold channel) (k(2)); and 3) rapid iron loss from site 2 to DES (k(1)).
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http://dx.doi.org/10.1016/j.jinorgbio.2010.11.002 | DOI Listing |
Metallomics
April 2019
Department of Chemistry, State University of New York, Potsdam, NY 13676, USA.
The excessively high and inconsistent literature values for Km,Fe and Km,O2 prompted us to examine the iron oxidation kinetics in ferritin, the major iron storage protein in mammals, and to determine whether a traditional Michaelis-Menten enzymatic behavior is obeyed. The kinetics of Fe(ii) oxidation and mineralization catalyzed by three different types of ferritins (recombinant human homopolymer 24H, HuHF, human heteropolymer ∼21H:3L, HL, and horse spleen heteropolymer ∼3.3H:20.
View Article and Find Full Text PDFChemistry
July 2017
Istituto per lo Studio delle Macromolecole, CNR, Via Corti 12, 20133, Milano, Italy.
Ferritin is a ubiquitous nanocage protein, which can accommodate up to thousands of iron atoms inside its cavity. Aside from its iron storage function, a new role as a fatty acid binder has been proposed for this protein. The interaction of apo horse spleen ferritin (HoSF) with a variety of lipids has been here investigated through NMR spectroscopic ligand-based experiments, to provide new insights into the mechanism of ferritin-lipid interactions, and the link with iron mineralization.
View Article and Find Full Text PDFJ Inorg Biochem
February 2011
Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602, United States.
The rate of Fe(3+) release from horse spleen ferritin (HoSF) was measured using the Fe(3+)-specific chelator desferoxamine (DES). The reaction consists of two kinetic phases. The first is a rapid non-linear reaction followed by a slower linear reaction.
View Article and Find Full Text PDFBr J Nutr
January 2010
Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK.
Long-chain n-3 PUFA from fish oil protect against death from CHD but mechanisms are not well understood. Preliminary results indicate that fish oil may affect the enzyme soluble epoxide hydrolase (sEH) and influence inflammatory pathways in a time-dependent manner. In the present study male apoE knockout (Apoe-/-) mice were randomised to three dietary groups receiving a high-fat high-cholesterol diet supplemented with 2 % (w/w) high-oleic acid sunflower-seed (HOSF) oil, DHA oil or fish oil.
View Article and Find Full Text PDFAm J Clin Nutr
August 2009
Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University, 6703 HD Wageningen, Netherlands.
Background: Polyunsaturated fatty acids can have beneficial effects on human immune cells, such as peripheral blood mononuclear cells (PBMCs). However, the mechanisms of action of polyunsaturated fatty acids on immune cells are still largely unknown.
Objective: The objective was to examine the effects of supplementation with the polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on whole-genome PBMC gene expression profiles, in healthy Dutch elderly subjects participating in a double-blind trial, by using whole-genome transcriptomics analysis.
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