Gray J S, Yang B Y, Hull S R, Venzke D P, Montgomery R
Department of Biochemistry, College of Medicine, University of Iowa, Iowa City 52242, USA.
Glycobiology. 1996 Jan;6(1):23-32. doi: 10.1093/glycob/6.1.23.
Soybean hull peroxidase (SBP, E.C. 1.11.1.7), an anionic glycoprotein, was found to contain 18.2% carbohydrate with the average composition: 2 mol GlcNAc, 3.3 mol Man, 0.9 mol Fuc, and 0.7 mol Xyl. The oligosaccharides of SBP, after release with glycopeptidase A, were investigated by a combination of high pH anion exchange chromatography with pulsed amperometric detection, methylation analysis and matrix assisted laser desorption/ionization-time-of-flight mass spectrometry. The structure of the major oligosaccharide, accounting for 60 to 65% of the total, is Man alpha 1-->6(Man beta 1-->3)(Xyl beta 1-->2)Man beta 1-->4GlcNAc beta 1-->4(Fuc alpha 1-->3)GlcNAc. A further 20 to 25% of the released oligosaccharides belong to the (Xyl)xManm(Fuc)fGlcNAc2 (m = 2, 4, 5, 6; f = 0 or 1, x = 0 or 1) family. The rest of the oligosaccharides were of the high-mannose type. Investigation of the six tryptic fractions containing carbohydrate revealed considerable heterogeneity in the N-linked oligosaccharides present in each fraction. The major glycan (4, Table III) was present in each fraction. Two of the fractions contained the major part of the high-mannose type glycans, ManmGlcNAc2 (m = 5-9), the major species being Man7GlcNAc2. The other four fractions contained mainly members of the (Xyl)xManm(Fuc)fGlcNAc2 (m = 2, 4, 5, 6; f = 0 or 1; x = 0 or 1) family. Methylation analysis of the holo- and apo-SBP provide support for the structures proposed for the oligosaccharides as well as for the heterogeneity of the glycopeptide fractions.
大豆壳过氧化物酶（SBP，E.C. 1.11.1.7）是一种阴离子糖蛋白，发现其含有18.2%的碳水化合物，平均组成为：2摩尔氨基葡萄糖、3.3摩尔甘露糖、0.9摩尔岩藻糖和0.7摩尔木糖。用糖肽酶A释放后，通过高pH阴离子交换色谱与脉冲安培检测、甲基化分析以及基质辅助激光解吸/电离飞行时间质谱联用对SBP的寡糖进行了研究。占总量60%至65%的主要寡糖结构为Manα1→6(Manβ1→3)(Xylβ1→2)Manβ1→4GlcNAcβ1→4(Fucα1→3)GlcNAc。另外20%至25%的释放寡糖属于(Xyl)xManm(Fuc)fGlcNAc2（m = 2、4、5、6；f = 0或1，x = 0或1）家族。其余寡糖为高甘露糖型。对六个含碳水化合物的胰蛋白酶水解片段的研究表明，每个片段中存在的N-连接寡糖具有相当大的异质性。主要聚糖（表III中的4）存在于每个片段中。其中两个片段含有高甘露糖型聚糖的主要部分，即ManmGlcNAc2（m = 5 - 9），主要种类为Man7GlcNAc2。其他四个片段主要含有(Xyl)xManm(Fuc)fGlcNAc2（m = 2、4、5、6；f = 0或1；x = 0或1）家族的成员。全酶和脱辅基SBP的甲基化分析为所提出的寡糖结构以及糖肽片段的异质性提供了支持。
