Recent progresses in the accumulation of metal ions into the apo-ferritin cage: Experimental and theoretical perspectives

Abstract

Ferritin is a self-assembled 24-mer protein cage which is naturally designed for iron storage. Other than iron, the apo-ferritin cage template can accommodate various non-natural metal substrates such as metal ions, metal complexes, and organic molecules. Because of this property, the apo-ferritin template is utilized for preparing inorganic nanomaterials which include quantum dot, metal nanoparticle, metal oxide etc. Although current studies are largely focusing on preparation, the basis of nanomaterial formations such as metal ion deposition, translocation, core formation etc. are not clarified. Therefore, studying the process of metal ions immobilization in ferritin cage with detailed coordination structures is an important topic in the area of material chemistry to develop bioinspired nanomaterials with a fundamental understanding of specific metal–protein interaction. Until now, there are only a limited number of reports except iron, which describes the metal ions accumulation with details characterization by X-ray crystallography. In addition, theoretical calculations are providing important information, particularly the dynamics of the accumulation process of metal ions as well as conformational changes in the amino acid side chains. Under this background, the current review highlights the recent and significant progress on the metal ion accumulation process in order to design and construct novel ferritin-based bionanomaterials.