Role of glycoproteins in the uptake of L-14C-leucine by a synaptosomal fraction.
The present study deals with the effect of modification of membrane glycoproteins on the accumulation of amino acids by isolated synaptosomal fractions, measured by the uptake of 14C-leucine. Superficial sugar receptors were modified by concanavalin A, neuraminidase, and neuraminidase followed by concanavalin A binding. It is demonstrated that neuraminidase treatment followed by concanavalin A binding results in significant diminution of 14C-leucine uptake. A similar effect was observed in experimental hypox followed by concanavalin A binding to isolated synaptosomal fractions. In this case, however, (Na+-K+) -ATPase activity remained unchanged. These results seem to indicate that 14C-leucine uptake was dependent on integrity of glycoprotein structure of synaptosomal membranes.
D000818:Animals; D002540:Cerebral Cortex / Q000201:enzymology; D005649:Fumarate Hydratase / Q000378:metabolism; D006023:Glycoproteins / Q000502:physiology*; D006168:Guinea Pigs; D000860:Hypoxia / Q000201:enzymology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007930:Leucine / Q000378:metabolism*; D008565:Membrane Proteins / Q000502:physiology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013574:Synaptosomes / Q000201:enzymology*
D006023:Glycoproteins; D008565:Membrane Proteins; D007770:L-Lactate Dehydrogenase; D005649:Fumarate Hydratase; D000254:Sodium-Potassium-Exchanging ATPase; D007930:Leucine