Surface differentiation of ferritin and apoferritin with atomic force microscopic techniques

Ru Hung Ho, Yu Hung Chen, Chong Mou Wang*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


In the study reported herein, we differentiated the structure of ferritin from that of its demetalated counterpart, apoferritin, using field-effect-based atomic force microscopic (AFM) techniques. When ferritin was subjected to conductive-mode AFM analysis, the protein resembled a pancake with a diameter of 10. nm adsorbed on the indium-doped tin-oxide substrate with its fourfold channel perpendicular to the substrate, whereas a flat, empty cavity was revealed for apoferritin. We also attempted to verify the conformational difference with magnetic-mode AFM. However, the resulting phase images failed to differentiate the proteins due to interference from the fringe effect. Despite this, the ferritin analysis revealed a sound correlation between the surface conductivity profiles and the phase profiles. In contrast, apoferritin showed a chaotic relationship in this respect. These results not only suggest that the magnetic domain of ferritin is limited to the iron aggregate in the core, but also demonstrate that AFM is a useful tool for protein conformation analysis.

Original languageEnglish
Pages (from-to)231-235
Number of pages5
JournalColloids and Surfaces B: Biointerfaces
Publication statusPublished - 2012 Jun 1


  • Atomic force microscopy
  • Ferritin
  • Protein conformation analysis

ASJC Scopus subject areas

  • Biotechnology
  • Surfaces and Interfaces
  • Physical and Theoretical Chemistry
  • Colloid and Surface Chemistry


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