Quinolinic acid, an endogenous metabolite with neurotoxic properties, alters the physical state of membrane proteins in human erythrocytes.
Quinolinic acid (2,3-pyridinedicarboxylic acid), an endogenous, tryptophan metabolite, is neurotoxic when injected into rat striatum (1). To begin to investigate the molecular interactions of quinolinic acid with membranes, electron spin resonance studies of the effects of this neurotoxin on the physical state of lipids, proteins, and cell-surface sialic acid in human erythrocyte ghosts have been performed. Quinolinic acid induced a highly significant alteration in the physical state of membrane proteins (P less than 0.01) while that of sialic acid and membrane lipids was unaffected. These results are similar to those induced by ibotenic acid, an exogenous neurotoxin, and are discussed with reference to possible molecular characteristics of the interaction of these neurotoxins with membrane proteins.
D004578:Electron Spin Resonance Spectroscopy; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D009498:Neurotoxins; D009525:Niacin / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology*; D017378:Quinolinic Acid; D011805:Quinolinic Acids / Q000494:pharmacology*; D013113:Spin Labels
D008565:Membrane Proteins; D009498:Neurotoxins; D011725:Pyridines; D011805:Quinolinic Acids; D013113:Spin Labels; D009525:Niacin; D017378:Quinolinic Acid