Kato S, Oda-Tamai S, Akamatsu N
Department of Biochemistry, St. Marianna University School of Medicine, Kawasaki, Japan.
Biochem J. 1988 Jul 1;253(1):59-66. doi: 10.1042/bj2530059.
[3H]Mannose-labelled glycopeptides in the slices of livers from neonatal and 1-, 2-, 3- and 5-week-old rats were characterized by column chromatographies on Sephadex G-50 and concanavalin A-Sepharose and by endo-beta-N-acetylglucosaminidase H digestion. The proportion of complex-type glycopeptides was increased with time until 2 weeks post partum and then returned to the neonatal level. This was mainly due to the increased proportion of concanavalin A-bound (biantennary) species. These changes were accompanied by consistent changes in the activities of processing enzymes in liver microsomal fraction, especially of N-acetylglucosaminyltransferase I. Complex-type glycopeptides from neonatal and 2- and 5-week-old rat livers were further characterized by column chromatographies on Bio-Gel P-6 and DE 52 DEAE-cellulose in combination with neuraminidase digestion. No significant difference was found between concanavalin A-bound species from neonatal liver and those from liver 5 weeks post partum, most of which were sialylated. Concanavalin A-bound species 2 weeks post partum were comparatively smaller in size and less sialylated. On the other hand, there was no significant difference among concanavalin A-unbound species from the three different sources, most of which were sialylated. Since glycoproteins from regenerating rat liver also contain a higher proportion of complex-type oligosaccharides, as previously reported, such changes in N-linked oligosaccharides of glycoproteins may be related to control of the growth of liver cells.
通过在葡聚糖G - 50和伴刀豆球蛋白A - 琼脂糖上进行柱色谱分析以及用内切β - N - 乙酰葡糖胺酶H消化，对新生大鼠以及1、2、3和5周龄大鼠肝脏切片中[³H]甘露糖标记的糖肽进行了表征。复合型糖肽的比例随时间增加，直至产后2周，然后恢复到新生水平。这主要是由于伴刀豆球蛋白A结合（双天线）型糖肽比例的增加。这些变化伴随着肝脏微粒体部分加工酶活性的持续变化，尤其是N - 乙酰葡糖胺转移酶I。通过在Bio - Gel P - 6和DE 52 DEAE - 纤维素上进行柱色谱分析并结合神经氨酸酶消化，进一步表征了新生大鼠以及2和5周龄大鼠肝脏的复合型糖肽。新生肝脏和产后5周肝脏中伴刀豆球蛋白A结合型糖肽之间未发现显著差异，其中大多数都被唾液酸化。产后2周的伴刀豆球蛋白A结合型糖肽尺寸相对较小且唾液酸化程度较低。另一方面，来自三种不同来源的未结合伴刀豆球蛋白A的糖肽之间没有显著差异，其中大多数都被唾液酸化。如先前报道，由于再生大鼠肝脏中的糖蛋白也含有较高比例的复合型寡糖，糖蛋白中N - 连接寡糖的这种变化可能与肝细胞生长的控制有关。
