Membrane damage by cytolysin A-III: effects of monovalent and divalent cations
The effects of monovalent and divalent cations on the hemolytic activity of Cerebratulus lacteus toxin A-III were studied. In PBS buffer, A-III activity is strongly inhibited by increasing the osmotic pressure with sodium chloride but not with sucrose. Different salts, whether permeant or impermeant show qualitatively similar inhibitory effects. In low ionic strength isotonic buffer the hemolytic activity of A-III is remarkably increased, the HC50 being shifted from 2 ..mu..g/ml to 20-30 ng/ml in Hepes-sucrose. This corresponds to a 50-100 fold increase in activity. The divalent cations Zn/sup 2 +/ and Ca/sup 2 +/ also inhibit A-III activity, 0.3 mM Zn/sup 2 +/ totally abolishing A-III dependent hemolysis of human erythrocytes. Analogous studies on marker release from liposomes suggested that the effect of Zn/sup 2 +/ is due to its interaction with phospholipids. Inhibition of A-III activity by both mono and divalent cations is compatible with the importance of membrane surface potential in cytolysis. Screening of the surface potential by cations decreases membrane damage by A-III. Their data suggest a direct effect of cations on membrane phospholipid and are, to their knowledge, the first to show that cytolysin activity can be enhanced by decreasing ionic strength, in contrast to data obtained previously with other cytolysins.
- Research Organization:
- Univ. of Cincinnati, OH
- OSTI ID:
- 6065465
- Report Number(s):
- CONF-870644-
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 46:6; Conference: 78. annual meeting of the American Society of Biological Chemists conference, Philadelphia, PA, USA, 7 Jun 1987
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CALCIUM COMPOUNDS
BIOLOGICAL EFFECTS
ERYTHROCYTES
HEMOLYSIS
TOXINS
TOXICITY
ZINC COMPOUNDS
CATIONS
CELL MEMBRANES
INHIBITION
LIPOSOMES
MAN
PHOSPHOLIPIDS
VALENCE
ALKALINE EARTH METAL COMPOUNDS
ANIMALS
ANTIGENS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CELL CONSTITUENTS
CHARGED PARTICLES
ESTERS
IONS
LIPIDS
LYSIS
MAMMALS
MATERIALS
MEMBRANES
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANOIDS
PATHOLOGICAL CHANGES
PRIMATES
TOXIC MATERIALS
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology