The effect of solution pH on the structural stability of magnetoferritin

• Published in: Colloids and surfaces, B, Biointerfaces Vol. 156; pp. 375 - 381
• Main Authors: Balejčíková, L., Garamus, V.M., Avdeev, M.V., Petrenko, V.I., Almásy, L., Kopčanský, P.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.08.2017
• Subjects: Apoferritins - chemistry; Dynamic light scattering; Hydrogen-Ion Concentration; Iron - chemistry; Magnetoferritin solution; Molecular Structure; Oxides - chemistry; pH-dependent structure; Quantum Theory; Scattering, Small Angle; Small-angle X-ray scattering; Solutions; Structure and stability; X-Ray Diffraction; Structure and stability; Magnetoferritin solution; Dynamic light scattering; pH-dependent structure; Small-angle X-ray scattering
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2017.05.036

[Display omitted] •The highest stability of magnetoferritin was shown for the region of pH=7-9.•The “full protein shell” was confirmed in supernatant at pH∼4.•The lowest stability of magnetoferritin was observed at low pH below 6. The structural stability of magnetoferritin, a synthetic analogue of ferritin, at various pH levels is assessed here. The structural and electrical properties of the complexes were determined by small-angle X-ray scattering (SAXS), dynamic light scattering (DLS) and zeta potential measurements. At pH 3−6 a reduction of electrostatic repulsion on the suspended colloids resulted in aggregation and sedimentation of magnetoferritin. At neutral to slightly alkaline conditions (pH 7–9) the magnetoferritin structure was stable for lower iron loadings. Higher solution pH 10–12 induced destabilization of the protein structure and dissociation of subunits. Increasing the loading factor in the MFer complex leads to decrease of the stability versus pH changes.