Gamma-glutamyl transpeptidase in brain capillaries: possible site of a blood-brain barrier for amino acids.
A fraction containing capillaries and rich in gamma-glutamyl transpeptidase was isolated from homogenates of bovine brain cortex by density gradient centrifugation. The enzyme was localized in the endothelial cells by a histochemical procedure. gamma-Glutantyl transpeptidase may function in the transfer of some amino acids across the blood-brain barrier.
D000469:Alkaline Phosphatase / Q000302:isolation & purification; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001812:Blood-Brain Barrier; D002196:Capillaries / Q000201:enzymology*; D002417:Cattle; D002499:Centrifugation, Density Gradient; D002540:Cerebral Cortex / Q000098:blood supply / Q000201:enzymology*; D004727:Endothelium / Q000201:enzymology; D009708:Nucleotidases / Q000302:isolation & purification; D005723:gamma-Glutamyltransferase / Q000302:isolation & purification* / Q000378:metabolism
D000596:Amino Acids; D005723:gamma-Glutamyltransferase; D009708:Nucleotidases; D000469:Alkaline Phosphatase