The effect of putative nucleation sites on the loading and stability of iron in ferritin

Shu Hui Juan, Steven D. Aust

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

The L chain of the iron storage protein ferritin contains more putative nucleation sites in the core (Glu53, 56, 57, 60, and 63) than does the H chain (Glu61, 64, and 67). Recombinant DNA techniques were used to investigate the role of these putative nucleation sites on iron loading by ceruloplasmin and on the stability of the iron core. Recombinant rat liver ferritin H chain homopolymer and the two mutants (E61A and E61A-E64A), containing three, two and one nucleation sites, respectively, loaded up to 2010 ± 50, 2010 ± 40, and 1950 ± 40 atoms of iron per ferritin, respectively. However, the mutations resulted in a 50% decrease in the rate of iron loading by ceruloplasmin. The ferritin variants incorporated the same amount of phosphate after iron loading (410 ± 20, 400 ± 30, and 420 ± 20 atoms per ferritin, respectively). The stability of the iron cores prior to phosphate incorporation, assessed by the rate of iron release by 10 mM EDTA and the paraquat cation radical, corresponded to numbers of proposed nucleation sites. The subsequent incorporation of phosphate seemed to stabilize the iron core and minimized the effect of numbers of putative nucleation sites in ferritin on the rate of iron release by EDTA and the paraquat cation radical. After incorporation of phosphate the ferritins behaved similarly to the native rat liver ferritin with respect to the rate of iron release by the paraquat cation radical.

Original languageEnglish
Pages (from-to)259-265
Number of pages7
JournalArchives of Biochemistry and Biophysics
Volume350
Issue number2
DOIs
Publication statusPublished - Feb 15 1998
Externally publishedYes

Fingerprint

Ferritins
Nucleation
Iron
Paraquat
Phosphates
Cations
Ceruloplasmin
Edetic Acid
Liver
Rats
Apoferritins
Atoms
Recombinant DNA
Homopolymerization
Mutation

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

Cite this

The effect of putative nucleation sites on the loading and stability of iron in ferritin. / Juan, Shu Hui; Aust, Steven D.

In: Archives of Biochemistry and Biophysics, Vol. 350, No. 2, 15.02.1998, p. 259-265.

Research output: Contribution to journalArticle

@article{dc395f68a299498b83a9484f72c73618,
title = "The effect of putative nucleation sites on the loading and stability of iron in ferritin",
abstract = "The L chain of the iron storage protein ferritin contains more putative nucleation sites in the core (Glu53, 56, 57, 60, and 63) than does the H chain (Glu61, 64, and 67). Recombinant DNA techniques were used to investigate the role of these putative nucleation sites on iron loading by ceruloplasmin and on the stability of the iron core. Recombinant rat liver ferritin H chain homopolymer and the two mutants (E61A and E61A-E64A), containing three, two and one nucleation sites, respectively, loaded up to 2010 ± 50, 2010 ± 40, and 1950 ± 40 atoms of iron per ferritin, respectively. However, the mutations resulted in a 50{\%} decrease in the rate of iron loading by ceruloplasmin. The ferritin variants incorporated the same amount of phosphate after iron loading (410 ± 20, 400 ± 30, and 420 ± 20 atoms per ferritin, respectively). The stability of the iron cores prior to phosphate incorporation, assessed by the rate of iron release by 10 mM EDTA and the paraquat cation radical, corresponded to numbers of proposed nucleation sites. The subsequent incorporation of phosphate seemed to stabilize the iron core and minimized the effect of numbers of putative nucleation sites in ferritin on the rate of iron release by EDTA and the paraquat cation radical. After incorporation of phosphate the ferritins behaved similarly to the native rat liver ferritin with respect to the rate of iron release by the paraquat cation radical.",
author = "Juan, {Shu Hui} and Aust, {Steven D.}",
year = "1998",
month = "2",
day = "15",
doi = "10.1006/abbi.1997.0523",
language = "English",
volume = "350",
pages = "259--265",
journal = "Archives of Biochemistry and Biophysics",
issn = "0003-9861",
publisher = "Academic Press Inc.",
number = "2",

}

TY - JOUR

T1 - The effect of putative nucleation sites on the loading and stability of iron in ferritin

AU - Juan, Shu Hui

AU - Aust, Steven D.

PY - 1998/2/15

Y1 - 1998/2/15

N2 - The L chain of the iron storage protein ferritin contains more putative nucleation sites in the core (Glu53, 56, 57, 60, and 63) than does the H chain (Glu61, 64, and 67). Recombinant DNA techniques were used to investigate the role of these putative nucleation sites on iron loading by ceruloplasmin and on the stability of the iron core. Recombinant rat liver ferritin H chain homopolymer and the two mutants (E61A and E61A-E64A), containing three, two and one nucleation sites, respectively, loaded up to 2010 ± 50, 2010 ± 40, and 1950 ± 40 atoms of iron per ferritin, respectively. However, the mutations resulted in a 50% decrease in the rate of iron loading by ceruloplasmin. The ferritin variants incorporated the same amount of phosphate after iron loading (410 ± 20, 400 ± 30, and 420 ± 20 atoms per ferritin, respectively). The stability of the iron cores prior to phosphate incorporation, assessed by the rate of iron release by 10 mM EDTA and the paraquat cation radical, corresponded to numbers of proposed nucleation sites. The subsequent incorporation of phosphate seemed to stabilize the iron core and minimized the effect of numbers of putative nucleation sites in ferritin on the rate of iron release by EDTA and the paraquat cation radical. After incorporation of phosphate the ferritins behaved similarly to the native rat liver ferritin with respect to the rate of iron release by the paraquat cation radical.

AB - The L chain of the iron storage protein ferritin contains more putative nucleation sites in the core (Glu53, 56, 57, 60, and 63) than does the H chain (Glu61, 64, and 67). Recombinant DNA techniques were used to investigate the role of these putative nucleation sites on iron loading by ceruloplasmin and on the stability of the iron core. Recombinant rat liver ferritin H chain homopolymer and the two mutants (E61A and E61A-E64A), containing three, two and one nucleation sites, respectively, loaded up to 2010 ± 50, 2010 ± 40, and 1950 ± 40 atoms of iron per ferritin, respectively. However, the mutations resulted in a 50% decrease in the rate of iron loading by ceruloplasmin. The ferritin variants incorporated the same amount of phosphate after iron loading (410 ± 20, 400 ± 30, and 420 ± 20 atoms per ferritin, respectively). The stability of the iron cores prior to phosphate incorporation, assessed by the rate of iron release by 10 mM EDTA and the paraquat cation radical, corresponded to numbers of proposed nucleation sites. The subsequent incorporation of phosphate seemed to stabilize the iron core and minimized the effect of numbers of putative nucleation sites in ferritin on the rate of iron release by EDTA and the paraquat cation radical. After incorporation of phosphate the ferritins behaved similarly to the native rat liver ferritin with respect to the rate of iron release by the paraquat cation radical.

UR - http://www.scopus.com/inward/record.url?scp=0031847387&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031847387&partnerID=8YFLogxK

U2 - 10.1006/abbi.1997.0523

DO - 10.1006/abbi.1997.0523

M3 - Article

C2 - 9473300

AN - SCOPUS:0031847387

VL - 350

SP - 259

EP - 265

JO - Archives of Biochemistry and Biophysics

JF - Archives of Biochemistry and Biophysics

SN - 0003-9861

IS - 2

ER -