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11:11
Determination of Plasma Membrane Partitioning for Peripherally-associated Proteins
Published on: June 15, 2018
Role of zinc in plasma membrane function.
1Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA.
The Journal of Nutrition
|May 10, 2000
Summary
Zinc deficiency impairs cell membrane function, particularly calcium uptake, leading to issues like bleeding and neuropathy. Restoring zinc levels quickly reverses these effects, suggesting a defect in calcium channels is the primary biochemical issue.
Area of Science:
- Biochemistry
- Cell Biology
- Nutritional Science
Background:
- Plasma zinc concentration is a standard measure of zinc status but is insufficient alone.
- Zinc deficiency can manifest in various physiological impairments, including bleeding disorders and neurological issues.
- Identifying the primary biochemical defect in zinc deficiency is crucial for understanding its pathogenesis.
Purpose of the Study:
- To identify the first limiting biochemical defect in animals fed zinc-deficient diets.
- To investigate the role of plasma membrane proteins and calcium uptake in zinc deficiency.
- To elucidate the mechanisms underlying impaired platelet aggregation and neuropathy in zinc-deficient states.
Main Methods:
- Induction of zinc deficiency in animal models (rats and guinea pigs).
- Assessment of platelet aggregation, red blood cell osmotic fragility, and synaptic vesicle function.
- Analysis of plasma membrane protein changes and calcium ion (Ca2+) uptake.
- Evaluation of the effects of dietary zinc repletion and in vitro glutathione treatment.
Main Results:
- Zinc deficiency impairs platelet aggregation and red blood cell integrity, linked to decreased Ca2+ uptake and plasma membrane sulfhydryl concentration.
- Neuropathy and impaired synaptic vesicle Ca2+ uptake were observed in zinc-deficient guinea pigs.
- These impairments were rapidly reversible with dietary zinc repletion or in vitro glutathione treatment.
- A defect in calcium channels, potentially due to an abnormal sulfhydryl redox state, is postulated as the primary issue.
Conclusions:
- A defect in calcium channels is likely the first limiting biochemical defect in zinc deficiency.
- Impaired calcium uptake and subsequent second-messenger dysfunction result from an abnormal sulfhydryl redox state in membrane channel proteins.
- Understanding this mechanism provides insight into the cellular basis of zinc deficiency symptoms and potential therapeutic targets.
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