title: Effect of the charge distribution along the "ferritin-like" pores of the proteins from the Dps family on the iron incorporation process.
abstract: DNA-binding proteins from starved cells (Dps) differ in the number and position of charged residues along the "ferritin-like" pores that are used by iron to reach the ferroxidase center and the protein cavity. These differences are shown to affect significantly the electrostatic potential at the pores, which determines the extent of cooperativity in the iron uptake kinetics and thereby the mass distribution of the ferric hydroxide micelles inside the protein cavity. These conclusions are of biotechnological value in the preparation of protein-enclosed nanomaterials and are expected to apply also to ferritins. They were reached after characterization of the Dps from Listeria innocua, Helicobacter pylori, Thermosynechococcus elongatus, Escherichia coli, and Mycobacterium smegmatis. The characterization comprised the calculation of the electrostatic potential at the pores, determination of the iron uptake kinetics in the presence of molecular oxygen or hydrogen peroxide, and analysis of the proteins by means of the sedimentation velocity after iron incorporation.
authors.affiliation: Department of Biochemical Sciences, CNR Institute of Molecular Biology and Pathology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185, Rome, Italy.
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Ceci
authors.forename: Gisa
authors.initials: G
authors.lastname: Di Cecca
authors.forename: Mattia
authors.initials: M
authors.lastname: Falconi
authors.forename: Francesco
authors.initials: F
authors.lastname: Oteri
authors.forename: Carlotta
authors.initials: C
authors.lastname: Zamparelli
authors.forename: Emilia
authors.initials: E
authors.lastname: Chiancone
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry*; D005293:Ferritins / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016877:Oxidants / Q000737:chemistry; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D011487:Protein Conformation; D055672:Static Electricity
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C083911:DPS protein, Bacteria; D016877:Oxidants; D005293:Ferritins; D006861:Hydrogen Peroxide; D007501:Iron; D010100:Oxygen