The Impact of Redox, Hydrolysis and Dehydration Chemistry on the Structural and Magnetic Properties of Magnetoferritin Prepared in Variable Thermal Conditions

Abstract

Ferritin, a spherically shaped protein complex, is responsible for iron storage in bacteria, plants, animals, and humans. Various ferritin iron core compositions in organisms are associated with specific living requirements, health state, and different biochemical roles of ferritin isomers. Magnetoferritin, a synthetic ferritin derivative, serves as an artificial model system of unusual iron phase structures found in humans. We present the results of a complex structural study of magnetoferritins prepared by controlled in vitro synthesis. Using various complementary methods, it was observed that manipulation of the synthesis technology can improve the physicochemical parameters of the system, which is useful in applications. Thus, a higher synthesis temperature leads to an increase in magnetization due to the formation of the magnetite phase. An increase in the iron loading factor has a more pronounced impact on the protein shell structure in comparison with the pH of the aqueous medium. On the other hand, a higher loading factor at physiological temperature enhances the formation of an amorphous phase instead of magnetite crystallization. It was confirmed that the iron-overloading effect alone (observed during pathological events) cannot contribute to the formation of magnetite.

Variations in the Structural and Colloidal Stability of Magnetoferritin under the Impact of Technological Process Modulations

“…While the iron loading caused larger <D HYDR > for MFer07, the large <D HYDR > of MFer04 and MFer05 prepared at increased synthesis temperature up to 69 • C (near the protein denaturation point) was the result of the thermal decomposition of the protein, as we have shown previously [31]. However, the high synthesis temperature increases the preference for Fe 3 O 4 nanocrystal mineralization, necessarily accompanied by protein unfolding [30,31].…”

“…In our previous works, MFer protein structure destroying was observed and calculated from small-angle scattering data as the effect of LF, pH and temperature. [30,31].…”

“…Providing the ferritin globular structure is maintained, besides the ultraviolet light absorption, the light scattering on metallic nanocrystals in the Fer and MFer06 (bio)ferrofluid, depending on the LF, could occur. In our previous works, MFer protein structure destroying was observed and calculated from small-angle scattering data as the effect of LF, pH and temperature [30,31].…”

“…Standard physicochemical methods, including ultraviolet-visible spectroscopy, dynamic light scattering, and zeta-potential measurements, complemented our interpretations. The results show variations in protein arrangement that are dependent on the synthesis technology process, leading to the formation of various Fe-based minerals crystallization [30,31]. Specifically, the inorganic part of materials directly affects protein structure.…”