Stimulation and inhibition of human platelet membrane high-affinity GTPase by neomycin

FEBS Lett. 1988 Feb 29;229(1):49-53. doi: 10.1016/0014-5793(88)80795-6.


The effect of the inositol phospholipid-binding antibiotic neomycin was studied on high-affinity GTPase in human platelet membranes. At low concentrations (up to 1 mM), neomycin by itself stimulated a high-affinity GTPase. This GTPase stimulation was additive with that caused by the hormonal factors, prostaglandin E1 and epinephrine, but not with thrombin. At concentrations higher than 1 mM, neomycin reduced control GTPase activity and eliminated the stimulation caused by thrombin. The data suggest that neomycin by a presently unknown mechanism can regulate activity states of signal transducing GTP-binding proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blood Platelets / drug effects
  • Blood Platelets / enzymology*
  • Cell Membrane / drug effects
  • Cell Membrane / enzymology
  • Egtazic Acid / pharmacology
  • GTP Phosphohydrolases / antagonists & inhibitors
  • GTP Phosphohydrolases / metabolism*
  • Humans
  • Indomethacin / pharmacology
  • Kinetics
  • Neomycin / pharmacology*
  • Phosphoric Monoester Hydrolases / metabolism*
  • Thrombin / pharmacology


  • Egtazic Acid
  • Phosphoric Monoester Hydrolases
  • Thrombin
  • GTP Phosphohydrolases
  • Neomycin
  • Indomethacin