Chemistry at the protein-mineral interface in L-ferritin assists the assembly of a functional (μ³-oxo)Tris[(μ²-peroxo)] triiron(III) cluster.

ABSTRACT: X-ray structures of homopolymeric L-ferritin obtained by freezing protein crystals at increasing exposure times to a ferrous solution showed the progressive formation of a triiron cluster on the inner cage surface of each subunit. After 60 min exposure, a fully assembled (μ³-oxo)Tris[(μ²-peroxo)(μ²-glutamato-κO:κO')](glutamato-κO)(diaquo)triiron(III) anionic cluster appears in human L-ferritin. Glu60, Glu61, and Glu64 provide the anchoring of the cluster to the protein cage. Glu57 shuttles incoming iron ions toward the cluster. We observed a similar metallocluster in horse spleen L-ferritin, indicating that it represents a common feature of mammalian L-ferritins. The structures suggest a mechanism for iron mineral formation at the prote

SUBMITTER: Pozzi C 

PROVIDER: S-EPMC5347543 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature