Abstract
We have studied ADP-ribosyltransferase activity in platelet cytosol and electropermeabilized platelets. Cytosolic activity causes ADP-ribosylation or of a 37 kDa protein that is activated by increasing the concentration of potassium phosphate. ADP-ribosylation is inhibited by thiol reagents, an effect partially reversed by cholera toxin. In electropermeabilized platelets incubated with [alpha-32P]NAD, the 37 kDa protein is also ADP-ribosylated as are other proteins and albumin. Under these conditions, ADP-ribosylation is partially inhibited by nicotinamide. This experimental design could be used to determine the effect of cell agonists on endogenous ADP-ribosylation of proteins.
MeSH terms
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Adenosine Diphosphate Ribose / blood*
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Blood Platelets / enzymology*
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Cholera Toxin / pharmacology
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Chromatography, High Pressure Liquid
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Cytosol / enzymology
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Dithiothreitol / pharmacology
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Enzyme Activation / drug effects
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Humans
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Kinetics
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Magnesium / pharmacology
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NAD / metabolism
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Pertussis Toxin
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Phosphates / pharmacology
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Poly(ADP-ribose) Polymerases / blood*
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Potassium / pharmacology
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Potassium Compounds*
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Serum Albumin / metabolism
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Virulence Factors, Bordetella / pharmacology
Substances
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Phosphates
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Potassium Compounds
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Serum Albumin
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Virulence Factors, Bordetella
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NAD
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Adenosine Diphosphate Ribose
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Cholera Toxin
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potassium phosphate
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Poly(ADP-ribose) Polymerases
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Pertussis Toxin
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Magnesium
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Potassium
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Dithiothreitol