Unknown

Dataset Information

0

Defining the roles of the threefold channels in iron uptake, iron oxidation and iron-core formation in ferritin: a study aided by site-directed mutagenesis.


ABSTRACT: This paper aims to define the role of the threefold intersubunit channels in iron uptake and sequestration processes in the iron-storage protein, ferritin. Iron uptake, measured as loss of availability of Fe(II) to ferrozine (due to oxidation), has been studied in recombinant human H-chain ferritins bearing amino acid substitutions in the threefold channels or ferroxidase centres. Similar measurements with recombinant horse L-chain ferritin are compared. It is concluded that significant Fe(II) oxidation occurs only at the H-chain ferroxidase centres and not in the threefold channels, although this route is used by Fe(II) for entry. Investigations by Mössbauer and u.v.-difference spectroscopy show that part of the iron oxidized by H-chain ferritin returns to the threefold channels as Fe(III). This monomeric Fe(III) can be displaced by addition of Tb(III). Fe(III) also moves into the cavity for formation of the iron-core mineral, ferrihydrite. Iron incorporated into ferrihydrite becomes kinetically inert.

SUBMITTER: Treffry A 

PROVIDER: S-EPMC1137755 | biostudies-other | 1993 Dec

REPOSITORIES: biostudies-other

Similar Datasets

| S-EPMC7204511 | biostudies-literature
| S-EPMC1137754 | biostudies-other
| S-EPMC4653698 | biostudies-literature
| S-EPMC2771142 | biostudies-literature
| S-EPMC2175162 | biostudies-literature
| S-EPMC3074017 | biostudies-literature
| S-EPMC3936105 | biostudies-literature
| S-EPMC1217510 | biostudies-other
| S-EPMC5647560 | biostudies-literature
| S-EPMC3663513 | biostudies-literature