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Membrane permeabilization induced by discodermin A, a novel marine bioactive peptide
1Radio Isotope Center, Graduate School of Agriculture and Life Studies, The University of Tokyo, Bunkyo-Ku, Tokyo 113-8657, Japan. akoita@mail.ecc.u-tokyo.ac.jp
Toxicon : Official Journal of the International Society on Toxinology
|September 9, 2000
Summary
Discodermin A, a marine peptide, increases cell membrane permeability in vascular tissues. This effect may involve interactions with membrane phospholipids, impacting calcium and ATP transport.
Area of Science:
- Marine Biology
- Biochemistry
- Pharmacology
Background:
- Discodermin A (DC-A) is a novel bioactive peptide from the sea sponge Discodermia kiiensis.
- Vascular smooth muscle cells and tissues are crucial for regulating blood pressure and flow.
Purpose of the Study:
- To investigate the effects of DC-A on vascular smooth muscle cells and tissues.
- To elucidate the mechanism by which DC-A affects cell membrane permeability.
Main Methods:
- Confocal laser microscopy was used to assess plasma membrane permeabilization.
- Vascular tissues were treated with DC-A, Ca(2+), and ATP to evaluate contraction.
- Lactate dehydrogenase leakage was measured to assess membrane integrity.
Main Results:
- DC-A permeabilized A10 cell plasma membranes to fluorescent agents in a concentration-dependent manner.
- DC-A increased vascular tissue permeability to Ca(2+) and ATP, inducing sustained contraction.
- Higher concentrations of DC-A (30 microM) significantly increased lactate dehydrogenase leakage.
Conclusions:
- DC-A exhibits a permeabilizing effect on the plasma membrane.
- This effect is likely mediated by the interaction of DC-A's hydrophobic N-terminal residues with membrane phospholipids.
- DC-A's impact on membrane permeability has implications for vascular function.