Kuijer R, van de Stadt R J, van Kampen G P, de Koning M H, van de Voorde-Vissers E, van der Korst J K
Arthritis Rheum. 1986 Oct;29(10):1248-55. doi: 10.1002/art.1780291010.
Proteoglycans (A1 fractions) were extracted with 4M guanidine hydrochloride (GuHCl) from human articular cartilage samples of a wide age range. Distinctions were made between hip and knee, and upper and lower layers. The residues of these extractions were digested with purified collagenase, and a second extraction with 4M GuHCl was performed, which yielded appreciable amounts of proteoglycans. When proteoglycans from second extractions were compared with those from first extractions, the following changes were observed: an increase in chondroitin sulfate; a relative decrease in keratan sulfate; a decrease in protein content; and a decrease in the ratio of chondroitin 6-sulfate to chondroitin 4-sulfate. The same changes were found when nonaggregating proteoglycans were compared with proteoglycan aggregates, when proteoglycans from young cartilage were compared with those from mature cartilage, when proteoglycans from knee cartilage were compared with those from hip cartilage, and when proteoglycans from upper layers of cartilage were compared with those from deeper layers. It is suggested that the differences found between first and second extractions of cartilage, between upper and lower layers of cartilage, and between knee and hip cartilage are caused by variations in the relative amount of nonaggregating proteoglycans and/or variations in proteoglycan size.
采用4M盐酸胍（GuHCl）从不同年龄段的人关节软骨样本中提取蛋白聚糖（A1组分）。区分了髋关节和膝关节以及上层和下层。这些提取物的残渣用纯化的胶原酶消化，然后用4M GuHCl进行第二次提取，得到了相当数量的蛋白聚糖。将第二次提取物中的蛋白聚糖与第一次提取物中的蛋白聚糖进行比较时，观察到以下变化：硫酸软骨素增加；硫酸角质素相对减少；蛋白质含量降低；硫酸软骨素6-硫酸酯与硫酸软骨素4-硫酸酯的比例降低。当比较非聚集性蛋白聚糖与蛋白聚糖聚集体、年轻软骨中的蛋白聚糖与成熟软骨中的蛋白聚糖、膝关节软骨中的蛋白聚糖与髋关节软骨中的蛋白聚糖以及软骨上层中的蛋白聚糖与深层中的蛋白聚糖时，也发现了相同的变化。有人认为，软骨第一次和第二次提取物之间、软骨上层和下层之间以及膝关节和髋关节软骨之间的差异是由非聚集性蛋白聚糖的相对量变化和/或蛋白聚糖大小变化引起的。
