Reactivity of ferritin and the structure of ferritin-derived ferrihydrite.
BACKGROUND
In nature or in the laboratory, the roughly spherical interior of the ferritin protein is well suited for the formation and storage of a variety of nanosized metal oxy-hydroxide compounds which hold promise for a range of applications. However, the linkages between ferritin reactivity and the structure and physicochemical properties of the nanoparticle core, either native or reconstituted, remain only partly understood.


METHODS
Here we review studies, including those from our laboratory, which have investigated the structure of ferritin-derived ferrihydrite and reactivity of ferritin, both native and reconstituted. Selected proposed structure models for ferrihydrite are discussed along with the structural and genetic relationships that exist among several different forms of ferrihydrite. With regard to reactivity, the review will emphasize studies that have investigated the (photo)reactivity of ferritin and ferritin-derived materials with environmentally relevant gaseous and aqueous species.


CONCLUSIONS
The inorganic core formed from apoferritin reconstituted with varied amounts of Fe has the same structural topology as the inorganically derived ferrihydrite that is an important component of many environmental and soil systems. Reactivity of ferritin toward aqueous species resulting from the photoexcitation of the inorganic core of the protein shows promise for driving redox reactions relevant to environmental chemistry.


CONCLUSIONS
Ferritin-derived ferrihydrite is effectively maintained in a relatively unaggregated state, which improves reactivity and opens the possibility of future applications in environmental remediation. Advances in our understanding of the structure, composition, and disorder in synthetic, inorganically derived ferrihydrite are shedding new light on the reactivity and stability of ferrihydrite derived artificially from ferritin.
Michel
F Marc
FM
Department of Geosciences, Stony Brook University, Stony Brook, NY 11794, USA. fmichel@stanford.edu
Hosein
Hazel-Ann
HA
Hausner
Douglas B
DB
Debnath
Sudeep
S
Parise
John B
JB
Strongin
Daniel R
DR
D000818:Animals; D005290:Ferric Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D005293:Ferritins / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D006878:Hydroxides / Q000737:chemistry / Q000378:metabolism; D008954:Models, Biological; D008958:Models, Molecular; D010084:Oxidation-Reduction; D011487:Protein Conformation
D005290:Ferric Compounds; D006878:Hydroxides; C092844:ferric oxyhydroxide; D005293:Ferritins; C031356:hydroxide ion