Sugahara K, Masuda M, Harada T, Yamashina I, de Waard P, Vliegenthart J F
Department of Biological Chemistry, Faculty of Pharmaceutical Sciences, Kyoto University, Japan.
Eur J Biochem. 1991 Dec 18;202(3):805-11. doi: 10.1111/j.1432-1033.1991.tb16436.x.
From the carbohydrate-protein linkage region of whale cartilage proteoglycans, which bear predominantly chondroitin 4-sulfate, one nonsulfated, two monosulfated and one disulfated hexasaccharide alditols were isolated after exhaustive digestions with Actinase E and chondroitinase ABC, and subsequent beta-elimination. Their structures were analyzed by chondroitinase ACII digestion in conjunction with HPLC and by 500-MHz 1H-NMR spectroscopy. The nonsulfated compound (A) had the following conventional structure: delta GlcA(beta 1-3)-GalNAc(beta 1-4)GlcA(beta 1-3)Gal(beta 1-4)Xylol, where GlcA, delta GlcA and GalNAc are glucuronic acid; 4,5-unsaturated glucuronic acid and 2-deoxy-2-N-acetylamino-D-galactose, respectively. The other compounds were sulfated derivatives of compound A. Two monosulfated compounds (B and C) had an ester sulfate on C4 or C6 of the GalNAc residue, respectively and the disulfated compound (D) had two ester sulfate groups, namely, one on C4 of the GalNAc and the other on C4 of the Gal residue substituted by GlcA. The molar ratio of A/B/C/D was 0.21:0.16:0.36:0.27. The compound containing Gal-4-O-sulfate was previously isolated by us in the form of a sulfated glycoserine [delta GlcA(beta 1-3)GalNAc(4-O- sulfate)(beta 1-4)GlcA(beta 1-3)Gal(4-O-sulfate)(beta 1-3)-Gal(beta 1- 4)Xyl beta 1-O-Ser] from the carbohydrate-protein linkage region of rat chondrosarcoma chondroitin-4-sulfate proteoglycans [Sugahara K., Yamashina, I., DeWaard, P., Van Halbeek, H. & Vliegenthart, J.F.G. (1988) J. Biol. Chem. 263, 10,168-10,174]. The discovery of this structure in the carbohydrate-protein linkage region of chondroitin 4-sulfate proteoglycans from nontumorous cartilage indicates that it is not a tumor-associated product but rather a physiological biosynthetic product since it represents a significant proportion. The biological significance of this structure is discussed in relation to glycosaminoglycan biosynthesis.
从主要带有硫酸软骨素4-硫酸酯的鲸软骨蛋白聚糖的碳水化合物-蛋白质连接区域中，在用肌动蛋白酶E和软骨素酶ABC进行彻底消化，随后进行β-消除反应后，分离出了一种非硫酸化、两种单硫酸化和一种双硫酸化的六糖糖醇。通过软骨素酶ACII消化结合高效液相色谱法（HPLC）以及500兆赫的1H-核磁共振光谱对它们的结构进行了分析。非硫酸化化合物（A）具有以下常规结构：δ葡糖醛酸（β1-3）-N-乙酰半乳糖胺（β1-4）葡糖醛酸（β1-3）半乳糖（β1-4）木糖醇，其中葡糖醛酸、δ葡糖醛酸和N-乙酰半乳糖胺分别是葡糖醛酸、4,5-不饱和葡糖醛酸和2-脱氧-2-N-乙酰氨基-D-半乳糖。其他化合物是化合物A的硫酸化衍生物。两种单硫酸化化合物（B和C）分别在N-乙酰半乳糖胺残基的C4或C6上有一个硫酸酯，而双硫酸化化合物（D）有两个硫酸酯基团，即一个在N-乙酰半乳糖胺的C4上，另一个在被葡糖醛酸取代的半乳糖的C4上。A/B/C/D的摩尔比为0.21:0.16:0.36:0.27。我们之前从大鼠软骨肉瘤硫酸软骨素4-硫酸酯蛋白聚糖的碳水化合物-蛋白质连接区域中以硫酸化糖丝氨酸[δ葡糖醛酸（β1-3）N-乙酰半乳糖胺（4-O-硫酸酯）（β1-4）葡糖醛酸（β1-3）半乳糖（4-O-硫酸酯）（β1-3）-半乳糖（β1-4）木糖β1-O-丝氨酸]的形式分离出了含有半乳糖-4-O-硫酸酯的化合物。在非肿瘤性软骨的硫酸软骨素4-硫酸酯蛋白聚糖的碳水化合物-蛋白质连接区域中发现这种结构表明它不是肿瘤相关产物，而是一种生理生物合成产物，因为它占了相当大的比例。结合糖胺聚糖生物合成讨论了这种结构的生物学意义。
