Related Experiment Videos
The role of ascorbate in biomembrane energetics
Annals of the New York Academy of Sciences
|January 1, 1987
Summary
This study explores how membrane translocations are energized, focusing on NADH-ascorbate free radical oxidoreductase. This enzyme may drive membrane movement by generating proton gradients or membrane potentials.
Area of Science:
- Cellular Biology
- Biochemistry
- Membrane Transport
Background:
- Mechanisms energizing membrane translocations are not fully understood.
- Existing knowledge primarily focuses on ATP-driven processes.
- Alternative energy-generating mechanisms for membranes require further investigation.
Purpose of the Study:
- To investigate the role of transmembrane redox constituents in energizing membranes.
- To explore the function of NADH-ascorbate free radical oxidoreductase in membrane energization.
- To elucidate the potential contribution of redox activity to membrane translocations.
Main Methods:
- Focused on transmembrane microsomal and plasma membrane redox constituents.
- Investigated NADH-ascorbate free radical (mono- or semidehydroascorbate) oxidoreductase activity.
- Examined evidence linking redox activity to membrane translocations, including clathrin coating.
Main Results:
- NADH-ascorbate free radical oxidoreductase activity is localized to the Golgi apparatus, transport vesicles, and plasma membrane.
- Evidence suggests this activity is linked to membrane translocations, with apparent activation by clathrin.
- Results support a role for ascorbate free radical in electron transport for driving translocations via proton gradients or membrane potentials.
Conclusions:
- The ascorbate free radical may act as an electron acceptor in coated membranes to drive translocations.
- Plasma membrane redox may regulate cell growth, potentially less dependent on ascorbate free radical than internal endomembranes.
- Redox function in internal endomembranes might rely on the regeneratable ascorbate free radical pool.