The metabolism of sialic acid in cystic fibrosis.
The activities of plasma and fibroblast cytidine 5'-monophosphate-sialic acid:glycoprotein sialyltransferases of patients with cystic fibrosis have been found to be within the range of activities of age- and sex-matched normal controls when asialofetuin served as the sialic acid acceptor. The use of desialylated preparations of purified human plasma alpha 2-macroglobulin, as an acceptor, demonstrated 35 to 52% reduction in the incorporation of sialic acid into the alpha 2-macroglobulin from patients with cystic fibrosis as compared to that of alpha 2-macroglobulin from normal controls. The reduced sialylation was dependent upon the source of the alpha 2-macroglobulin acceptor but independent of the source (cystic fibrosis or normal) of the sialyltransferase enzyme. Using radiolabeled precursors, the rates of the synthesis of N-acetylneuraminic acid from N-acetyl-D-mannosamine, the release of sialic acid from glycoproteins and the conversion of free sialic acid into CMP-sialic acid have been determined in cultured skin fibroblasts from patients with cystic fibrosis and found to be not significantly different from those of normal controls.
D000293:Adolescent; D001212:Asialoglycoproteins; D002648:Child; D003550:Cystic Fibrosis / Q000097:blood / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D006023:Glycoproteins / Q000096:biosynthesis / Q000378:metabolism; D006801:Humans; D008297:Male; D000216:N-Acylneuraminate Cytidylyltransferase / Q000378:metabolism; D009439:Neuraminidase / Q000378:metabolism; D012794:Sialic Acids / Q000097:blood / Q000378:metabolism*; D012799:Sialyltransferases / Q000378:metabolism; D012867:Skin / Q000378:metabolism; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
D001212:Asialoglycoproteins; D006023:Glycoproteins; D012794:Sialic Acids; D012799:Sialyltransferases; D000216:N-Acylneuraminate Cytidylyltransferase; D009439:Neuraminidase; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase