Leoni S, Marino M, Devirgiliis L C, Spagnuolo S, Beninati S, Mangiantini M T
Department of Cellular and Developmental Biology, University of Rome, La Sapienza, Italy.
Mech Ageing Dev. 1990 Nov;56(2):169-78. doi: 10.1016/0047-6374(90)90007-3.
The glycosylation pattern in isolated rat hepatocytes during pre- and post-natal development and senescence has been studied by following: the [14C]glucosamine and [3H]galactose incorporation into cellular glycoproteins and glycolipids and the activity of two microsomal enzymes, N-acetyl-glucosaminyl-1-P transferase and galactosyl transferase. The data show a lowered precursor incorporation into lipids and proteins in the fetus, newborn and old rats versus the adult. Only the galactosyl transferase activity is enhanced on the 19th and 22nd day of fetal life. The glucosamine and N-acetyl-glucosamine content in both soluble and protein bound fractions was increased, while the galactose content in lipids and proteins decreased in the fetal stage. The different sugar composition of the proteins, and the decreased glucosamine and galactose incorporation into the proteins, observed in the fetus, newborn and old rat, suggest a post-translational modification which may cause alterations in functions usually mediated by glycoproteins.
通过以下方法研究了出生前、出生后发育及衰老过程中分离的大鼠肝细胞的糖基化模式：[14C]葡萄糖胺和[3H]半乳糖掺入细胞糖蛋白和糖脂的情况，以及两种微粒体酶——N-乙酰葡糖胺-1-P转移酶和半乳糖基转移酶的活性。数据显示，与成年大鼠相比，胎儿、新生大鼠和老年大鼠中前体掺入脂质和蛋白质的量降低。仅在胎儿期第19天和第22天，半乳糖基转移酶活性增强。在胎儿期，可溶性部分和与蛋白质结合部分中的葡萄糖胺和N-乙酰葡糖胺含量增加，而脂质和蛋白质中的半乳糖含量降低。在胎儿、新生大鼠和老年大鼠中观察到的蛋白质糖组成不同，以及葡萄糖胺和半乳糖掺入蛋白质的量减少，提示存在翻译后修饰，这可能导致通常由糖蛋白介导的功能发生改变。
