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Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase
Published on: December 4, 2017
Iron-reducing activity of plasma membranes
Biochemistry International
|December 1, 1992
Summary
Transferrin receptors in human placental membranes mediate redox reactions, facilitating iron release. However, isolated receptors lack this oxidoreductase activity, suggesting a membrane-dependent function.
Area of Science:
- Cell Biology
- Biochemistry
- Physiology
Background:
- Human placental trophoblast plasma membranes contain transferrin receptors crucial for iron transport.
- The role of transferrin receptors in mediating redox reactions within the plasma membrane is not fully understood.
Purpose of the Study:
- To investigate the oxidoreductase activity of transferrin receptors in human placental plasma membranes.
- To determine if isolated transferrin receptors retain their redox activity.
Main Methods:
- Isolation of plasma membranes from human trophoblasts via differential centrifugation.
- Solubilization of membranes using nonionic detergent.
- Purification of transferrin receptors using affinity chromatography.
- Assay of NADH-ferricyanide oxidoreductive activity.
Main Results:
- Trophoblast plasma membrane vesicles exhibited NADH-ferricyanide oxidoreductive activity.
- Isolated transferrin receptors showed no measurable oxidoreductase activity.
- Redox activity was significantly reduced when using diferric transferrin as an electron acceptor.
Conclusions:
- Transferrin receptors mediate redox reactions within the plasma membrane, likely facilitating iron release.
- Biochemically isolated transferrin receptors do not exhibit intrinsic oxidoreductase activity.
- The plasma membrane environment is essential for transferrin receptor-mediated redox functions.
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