alexa The formation of Fe3+-transferrin-CO3(2-) via the binding and oxidation of Fe2+.
Biochemistry

Biochemistry

Bioenergetics: Open Access

Author(s): Kojima N, Bates GW

Abstract Share this page

Abstract This paper examines the reaction pathway in which Fe2+ is bound by apotransferrin and subsequently oxidized by O2 to yield Fe3+-transferrin-CO3(2-). The time course of the reaction follows a curved first order function suggesting somewhat different reactivities of the two transferrin binding sites. The initial velocity of the oxidation reaction follows saturation kinetics with regard to apotransferrin, Fe2+, and NaHCO3. We suggest an equilibrium between these components and Fe2+-transferrin-CO3(2-). The initial velocity is a linear function of O2 concentration. This is consistent with the rate-limiting step of the overall reaction being the oxidation of the Fe2+-transferrin-CO3(2-). A second order rate constant of approximately 4 X 10(3) M-1 s-1 was estimated for the oxidation of Fe2+-transferrin-CO3(2-) by O2. Oxidation by H2O2 is about 30 times faster. The reaction velocity increases with increasing pH between pH 6.0 and 7.5 Fe3+-transferrin-anion complexes are formed by the binding and oxidation of Fe2+ iun the presence of O2 and synergistic anions. The anion is found to have a strong effect on the reaction rate and provides additional evidence for the proposed reaction route. The presence of chelating agents also strongly affects the rate of Fe3+-transferrin-CO3(2-) formation. EDTA and N-(2-hydroxyethyl)ethylenediaminetriacetic acid severely depress the rate, while other chelating reagents have a moderately inhibiting effect. Thioglycolate is found to enhance the reaction by a factor of 9. The formation of a quaternary complex consisting of thioglycolate-Fe2+-transferrin-CO3(2-) is suggested. The results are correlated with an earlier study on the reductive release of iron from transferrin (Kojima, N., and Bates, G. W. (1979) J. Biol. Chem. 254, 8847-8854).
This article was published in J Biol Chem and referenced in Bioenergetics: Open Access

Relevant Expert PPTs

Relevant Speaker PPTs

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri, Food, Aqua and Veterinary Science Journals

Dr. Krish

[email protected]

1-702-714-7001 Extn: 9040

Clinical and Biochemistry Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Business & Management Journals

Ronald

[email protected]

1-702-714-7001Extn: 9042

Chemical Engineering and Chemistry Journals

Gabriel Shaw

[email protected]

1-702-714-7001 Extn: 9040

Earth & Environmental Sciences

Katie Wilson

[email protected]

1-702-714-7001Extn: 9042

Engineering Journals

James Franklin

[email protected]

1-702-714-7001Extn: 9042

General Science and Health care Journals

Andrea Jason

[email protected]

1-702-714-7001Extn: 9043

Genetics and Molecular Biology Journals

Anna Melissa

[email protected]

1-702-714-7001 Extn: 9006

Immunology & Microbiology Journals

David Gorantl

[email protected]

1-702-714-7001Extn: 9014

Informatics Journals

Stephanie Skinner

[email protected]

1-702-714-7001Extn: 9039

Material Sciences Journals

Rachle Green

[email protected]

1-702-714-7001Extn: 9039

Mathematics and Physics Journals

Jim Willison

[email protected]

1-702-714-7001 Extn: 9042

Medical Journals

Nimmi Anna

[email protected]

1-702-714-7001 Extn: 9038

Neuroscience & Psychology Journals

Nathan T

[email protected]

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

John Behannon

[email protected]

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

[email protected]

1-702-714-7001 Extn: 9042

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords