Characterization of bovine placental lactogen as a glycoprotein with N-linked and O-linked carbohydrate side chains.
Characterization of bovine placental lactogen as a glycoprotein with N-linked and O-linked carbohydrate side chains.
复制标题
牛胎盘催乳素作为具有 N-连接和 O-连接碳水化合物侧链的糖蛋白的表征。
作者：
K. Shimomura;R. Bremel
在之前的报告中，我们表明纯化的牛胎盘催乳素 (bPL) 以 31,000-33,000 Mr 范围内的两种亚型存在，每种亚型至少有 5 种等电变体，等电点 (pI) 4-6 相差约 2 个数量级。多种等电变体是牛激素所独有的。为了确定这些变体的性质，进行内切和外切糖水解酶消化以确定该激素是否被糖基化。在一维凝胶电泳上对放射性碘标记的 bPL 的肽/N-糖苷酶 F 和糖苷内切酶 F 消化物进行分析表明，两种异构体的 Mr 值从 31,000 下降到 24,000，从 33,000 下降到 26,000。用神经氨酸酶加混合外切糖苷酶的混合物进行消化导致 Mr 减少 4,000。用神经氨酸酶消化导致 Mr 减少 2,000。通过二维凝胶电泳对肽/N-糖苷酶 F 和神经氨酸酶处理的 bPL 进行进一步分析表明，等电变体从 pI 4.4-6.3 转变为 4.9-8.0。 N-连接上的唾液酸残基是 bPL 显着酸性特征的原因，但不能解释残留电荷异质性，因为在去除唾液酸后，不同的等电变体仍然存在。去除N-连接碳水化合物残基后蛋白质的表观Mr与PRL和GH相似。这些酶消化结果证明存在连接至天冬酰胺残基的β-酰胺基团的N-连接复合寡糖残基。对分子糖含量的分析与存在一个二触角 N 连接和两个 O 连接碳水化合物链一致。
In a previous report we showed that purified bovine placental lactogen (bPL) exists in two isoforms in the 31,000-33,000 Mr range, each with at least five isoelectric variants differing in approximately 2 orders of magnitude in isoelectric points (pI) 4-6. The multiple isoelectric variants are unique to the bovine hormone. In an effort to determine the nature of these variants endo- and exoglycohydrolase digestions were conducted to determine if this hormone was glycosylated. Analysis of peptide/N-glycosidase F and endoglycosidase F digests of radioiodinated bPL on one-dimensional gel electrophoresis showed a Mr decrease from 31,000 to 24,000 and 33,000 to 26,000 for the two isoforms. Digestion with a mixture of neuraminidase plus mixed exoglycosidases resulted in a Mr decrease of 4,000. Digestion with neuraminidase resulted in a Mr decrease of 2,000. Further analysis of peptide/N-glycosidase F- and neuraminidase-treated bPL by two-dimensional gel electrophoresis showed the isoelectric variants shifted from pI 4.4-6.3 to 4.9-8.0. The sialic acid residues on the N-linkage are responsible for the pronounced acidic character of bPL, but do not account for the residual charge heterogeneity as the different isoelectric variants persist after sialic acid removal. The apparent Mr of the protein after removal of N-linked carbohydrate residues is similar to that of PRL and GH. These enzymatic digestion results demonstrate the presence of N-linked complex oligosaccharide residues attached to the beta-amide group of an asparagine residue. Analyses of the sugar content of the molecule were consistent with the presence of one biantennary N-linked and two O-linked carbohydrate chains.
登录
查看更多内容
糖基化绵羊催乳素。
DOI：
10.1073/pnas.81.2.385
发表时间：
1984
影响因子：
11.1
作者：
Lewis,UJ;Singh,RN;Lewis,LJ;Seavey,BK;Sinha,YN
通讯作者：
Sinha,YN
小鼠肝膜中生长激素受体异质群体的鉴定和表征。
DOI：
--
发表时间：
1987
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Smith,WC;Talamantes,F
通讯作者：
Talamantes,F
DOI：
--
发表时间：
1985
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Green,ED;vanHalbeek,H;Boime,I;Baenziger,JU
通讯作者：
Baenziger,JU
影响因子：
4.8
作者：
Southard,JN;Thordarson,G;Talamantes,F
通讯作者：
Talamantes,F
来自妊娠中期小鼠概念的两种催乳素样糖蛋白激素复合物的纯化和部分表征。
影响因子：
4.8
作者：
Colosi,P;Ogren,L;Thordarson,G;Talamantes,F
通讯作者：
Talamantes,F