# Effect of iron oxide loading on magnetoferritin structure in solution as revealed by SAXS and SANS

## TL;DR

This study investigates how varying iron oxide content in magnetoferritin affects its structure in solution, revealing increased polydispersity and shell destabilization at higher loading factors through SAXS and SANS analysis.

## Contribution

It provides new insights into the structural effects of iron loading on magnetoferritin using combined SAXS and SANS techniques.

## Key findings

- Increased iron loading raises protein polydispersity.
- Higher iron content causes structural changes in the protein shell.
- Shell stability decreases significantly above a loading factor of ~150.

## Abstract

Synthetic biological macromolecule of magnetoferritin containing an iron oxide core inside a protein shell (apoferritin) is prepared with different content of iron. Its structure in aqueous solution is analyzed by small-angle synchrotron X-ray (SAXS) and neutron (SANS) scattering. The loading factor (LF) defined as the average number of iron atoms per protein is varied up to LF=800. With an increase of the LF, the scattering curves exhibit a relative increase in the total scattered intensity, a partial smearing and a shift of the match point in the SANS contrast variation data. The analysis shows an increase in the polydispersity of the proteins and a corresponding effective increase in the relative content of magnetic material against the protein moiety of the shell with the LF growth. At LFs above ~150, the apoferritin shell undergoes structural changes, which is strongly indicative of the fact that the shell stability is affected by iron oxide presence.

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Source: https://tomesphere.com/paper/1702.00350