Van Damme M P, Blackwell S T, Murphy W H, Preston B N
Biochemistry Department, Monash University, Clayton, Victoria, Australia.
Anal Biochem. 1992 Aug 1;204(2):250-7. doi: 10.1016/0003-2697(92)90235-y.
A colloid titration technique has been used to determine the sulfate and carboxylate content of various glycosaminoglycans and has been validated by comparing the results with data obtained using well-established techniques. The method has been applied to the measurement of the negative charge content of cartilage slices at various depths from the articular surface and to the determination of sulfate and carboxylate contents in bovine nasal septa. Titrations of nasal septa were performed on milled cartilage, on cartilage digested with papain and on proteoglycans purified by cesium chloride gradient centrifugation of guanidinium chloride extracts. The sulfate content was similar for all three preparations (0.5 mu eq per milligram dry cartilage). However, the carboxylate content determined on milled cartilage was 40% higher than that obtained for cartilage digested with papain or for purified proteoglycans; this implies the possible contribution of carboxyl groups from structural glycoproteins present in the extracellular matrix. The carboxylate content determined on purified proteoglycans was in excellent agreement with values calculated from chemical analyses.
一种胶体滴定技术已被用于测定各种糖胺聚糖的硫酸盐和羧酸盐含量，并通过将结果与使用成熟技术获得的数据进行比较而得到验证。该方法已应用于测量距关节表面不同深度的软骨切片的负电荷含量，以及测定牛鼻中隔中的硫酸盐和羧酸盐含量。对鼻中隔进行滴定的样品有研磨后的软骨、用木瓜蛋白酶消化后的软骨以及通过对氯化胍提取物进行氯化铯梯度离心纯化得到的蛋白聚糖。所有三种制剂的硫酸盐含量相似（每毫克干软骨0.5微当量）。然而，研磨后软骨中测定的羧酸盐含量比用木瓜蛋白酶消化后的软骨或纯化的蛋白聚糖中的羧酸盐含量高40%；这意味着细胞外基质中存在的结构糖蛋白中的羧基可能有贡献。纯化蛋白聚糖中测定的羧酸盐含量与化学分析计算的值非常一致。
