Deutsch A J, Midura R J, Plaas A H
Shriners Hospital for Crippled Children, Tampa, FL 33612, USA.
J Orthop Res. 1995 Mar;13(2):230-9. doi: 10.1002/jor.1100130211.
The structure of chondroitin sulfate on aggrecan isolated from the rib and proximal tibial growth plates of bovine fetuses was investigated, and the previously reported increase in the hydrodynamic size of chondroitin sulfate chains between the reserve and hypertrophic zones of the rib was confirmed in the tibial growth plate. Superose 6 gel chromatography, calibrated for chondroitin sulfate chain length by monosaccharide analysis, showed that the average molecular mass of chondroitin sulfate in the reserve and maturing zones of both growth plates was 21,600 and 30,400, respectively. Determination by capillary zone electrophoresis of the disaccharide composition of chains following chondroitinase digestion showed that delta Di-0S, delta Di-4S, and delta Di-6S together accounted for more than 98% of the disaccharides in the digests from all zones of both growth plates; delta disulfated and delta trisulfated disaccharides were not detected. Furthermore, this analysis revealed a gradient in chondroitin sulfate composition from the reserve to the hypertrophic zone, characterized by a marked increase in the content of delta Di-6S (from about 32% to about 52%) and a marked decrease in the content of delta Di-4S (from about 53% to about 35%). Moreover, this altered pattern of sulfation was detected on chains of all sizes in the hypertrophic zone, suggesting that a proportion of the reserve zone aggrecan might be removed and replaced with aggrecan rich in chondroitin-6-sulfate synthesized during the proliferative and maturation stages of the resident chondrocytes. These data are discussed in relation to the biosynthetic mechanisms that control chondroitin sulfate chain length and sulfation on aggrecan and their modification during chondrocyte proliferation, maturation, and hypertrophy in the growth plate.
对从牛胎儿肋骨和胫骨近端生长板分离出的聚集蛋白聚糖上硫酸软骨素的结构进行了研究，并且在胫骨生长板中证实了先前报道的肋骨储备区和肥大区之间硫酸软骨素链流体力学尺寸的增加。通过单糖分析校准硫酸软骨素链长度的Superose 6凝胶色谱显示，两个生长板储备区和成熟区中硫酸软骨素的平均分子量分别为21,600和30,400。通过毛细管区带电泳测定软骨素酶消化后链的二糖组成表明，δDi-0S、δDi-4S和δDi-6S一起占两个生长板所有区域消化物中二糖的98%以上；未检测到δ双硫酸化和δ三硫酸化二糖。此外，该分析揭示了从储备区到肥大区硫酸软骨素组成的梯度，其特征是δDi-6S含量显著增加（从约32%增加到约52%），而δDi-4S含量显著降低（从约53%降低到约35%）。此外，在肥大区所有大小的链上都检测到了这种改变的硫酸化模式，这表明储备区的一部分聚集蛋白聚糖可能被去除，并被驻留软骨细胞增殖和成熟阶段合成的富含硫酸软骨素-6-硫酸盐的聚集蛋白聚糖所取代。讨论了这些数据与控制聚集蛋白聚糖上硫酸软骨素链长度和硫酸化及其在生长板软骨细胞增殖、成熟和肥大过程中修饰的生物合成机制的关系。
