title: Studies on glycoconjugate metabolism in developing skeletal muscle membranes.
abstract: The postnatal development of mammalian skeletal muscle is characterized by changes in the properties of several key membrane glycoprotein enzymes and receptors. In the present study, CMP-sialic acid: fetuin sialyltransferase and CMP-sialic acid: lactosylceramide sialyltransferase activity was characterized in sarcolemma and sarcoplasmic reticulum membranes isolated from neonatal (0-1 week) and adult (8 week) rabbit skeletal muscle. CMP-sialic acid: fetuin sialyltransferase decreased by a factor of 10 in sarcolemma and 6 in sarcoplasmic reticulum during development, whereas CMP-sialic acid: lactosylceramide sialyltransferase activity decreased by a factor of 6 in sarcolemma and 18 in sarcoplasmic reticulum. The Km for CMP-sialic acid using the lipid acceptor declined during the development of sarcoplasmic reticulum (neonate vs. adult: 538 vs. 33 microM), but not in sarcolemma. The carbohydrate composition of sarcolemma was changed only with respect to total sialic acid content (neonate vs. adult: 67 vs. 44 nmol/mg). Similar analysis of sarcoplasmic reticulum carbohydrates showed decreases in total sialic acid, lipid-bound sialic acid, hexosamines and hexoses. The major ganglioside was GM3 for both types of membrane. No qualitative changes were observed in ganglioside composition comparing neonatal and adult membranes.
mesh_terms: D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D002462:Cell Membrane / Q000378:metabolism; D005260:Female; D006017:Glycolipids / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D007700:Kinetics; D008565:Membrane Proteins / Q000378:metabolism*; D024510:Muscle Development; D009132:Muscles / Q000378:metabolism; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000201:enzymology; D012799:Sialyltransferases / Q000378:metabolism*; D014166:Transferases / Q000378:metabolism*
chemical_list: D006017:Glycolipids; D006023:Glycoproteins; D008565:Membrane Proteins; D014166:Transferases; D012799:Sialyltransferases