Krusius T, Finne J, Rauvala H
Eur J Biochem. 1978 Dec 1;92(1):289-300. doi: 10.1111/j.1432-1033.1978.tb12747.x.
Glycopeptides with complex carbohydrate structure were isolated from delipidated human erythrocyte membranes after digestion with pronase. The poly(glycosyl)peptides isolated (apparent molecular weight 4000--13000) are suggested to contain 20--70 sugar residues in an alkali-stable saccharide chain linked through N-acetylglucosamine to asparagine. The main sugar components are galactose and N-acetylglucosamine, which together account for 80% of total sugars. That the compounds isolated are glycopeptides and not glycolipids is concluded from the following findings: only trace amounts of glucose and fatty acids were present, and no long-chain (sphingosine) bases could be detected; on the other hand, the amounts of mannose and amino acids found are compatible with an N-glycosidic poly(glycosyl)peptide structure. The structure of the poly(glycosyl)peptides was studied using methylation analysis, exoglycosidase treatments, acid hydrolysis of the native as well as the N-deacetylated glycopeptides, and chromium trioxide oxidation. The studies indicate that the poly(glycosyl)peptides contain a repeating-3)galactosyl(beta1-4)N-acetylglucosaminyl(beta1-structure with branch points at the C-6 of the galactose residues. The saccharide chains are terminated in N-acetylglucosaminyl, galactosyl, N-acetylneuraminyl(alpha2-3 and 6)galactosyl and fucosyl(alpha1-2)galactosyl residues, and they also contain blood group A and B determinants.
在用链霉蛋白酶消化后，从脱脂的人红细胞膜中分离出具有复杂碳水化合物结构的糖肽。分离得到的聚（糖基）肽（表观分子量4000 - 13000）被认为在通过N - 乙酰葡糖胺与天冬酰胺相连的碱稳定糖链中含有20 - 70个糖残基。主要的糖成分是半乳糖和N - 乙酰葡糖胺，它们合起来占总糖量的80%。从以下发现得出所分离的化合物是糖肽而非糖脂的结论：仅存在痕量的葡萄糖和脂肪酸，并且未检测到长链（鞘氨醇）碱；另一方面，所发现的甘露糖和氨基酸的量与N - 糖苷聚（糖基）肽结构相符。使用甲基化分析、外切糖苷酶处理、天然以及N - 脱乙酰化糖肽的酸水解和三氧化铬氧化来研究聚（糖基）肽的结构。研究表明聚（糖基）肽含有重复的 - 3）半乳糖基（β1 - 4）N - 乙酰葡糖胺基（β1 - 结构，在半乳糖残基的C - 6处有分支点。糖链以N - 乙酰葡糖胺基、半乳糖基、N - 乙酰神经氨酸基（α2 - 3和6）半乳糖基和岩藻糖基（α1 - 2）半乳糖基残基终止，并且它们还含有血型A和B决定簇。
