Department of Biochemical Sciences, CNR Institute of Molecular Biology and Pathology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185, Rome, Italy.
J Biol Inorg Chem. 2011 Aug;16(6):869-80. doi: 10.1007/s00775-011-0784-9. Epub 2011 May 6.
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.
饥饿细胞中的 DNA 结合蛋白（Dps）在“类铁蛋白”孔中的带电残基的数量和位置上存在差异，这些孔是铁到达亚铁氧化酶中心和蛋白质腔所必需的。这些差异显著影响了孔中的静电势，从而决定了铁摄取动力学中的协同程度，进而决定了蛋白质腔内部的氢氧化铁胶束的质量分布。这些结论在制备蛋白质包裹的纳米材料方面具有生物技术价值，预计也适用于铁蛋白。这些结论是在对无害李斯特菌、幽门螺杆菌、 elongatus 热球菌、大肠杆菌和耻垢分枝杆菌的 Dps 进行特性描述后得出的。这些特性描述包括计算孔中的静电势，确定在分子氧或过氧化氢存在下的铁摄取动力学，以及通过铁掺入后的沉降速度分析蛋白质。
