Roughley P J, White R J, Poole A R, Mort J S
Biochem J. 1984 Aug 1;221(3):637-44. doi: 10.1042/bj2210637.
High-buoyant-density proteoglycan aggregates could not be prepared from extracts of adult human cartilage by associative CsCl-density-gradient centrifugation with a starting density of 1.68 g/ml, even though proteoglycan subunits, hyaluronic acid and link proteins were all present. In contrast, aggregates could be prepared when extracts of neonatal human cartilage or bovine nasal cartilage were subjected to the same procedure. This phenomenon did not appear to be due to a defect within the hyaluronic acid-binding region of the adult proteoglycan subunit, but rather to an interference in the stability of the interaction between the proteoglycan subunit and hyaluronic acid towards centrifugation. The factor responsible for this instability was shown to reside within the low-density cartilage protein preparation obtained by direct dissociative CsCl-density-gradient centrifugation of the adult cartilage extract.
即使蛋白聚糖亚基、透明质酸和连接蛋白均存在，通过起始密度为1.68 g/ml的CsCl密度梯度离心法，也无法从成人软骨提取物中制备出高浮力密度的蛋白聚糖聚集体。相比之下，当对新生儿人软骨或牛鼻软骨提取物进行相同操作时，则可以制备出聚集体。这种现象似乎并非由于成人蛋白聚糖亚基的透明质酸结合区域存在缺陷，而是由于蛋白聚糖亚基与透明质酸之间的相互作用稳定性在离心过程中受到干扰。导致这种不稳定性的因素被证明存在于通过对成人软骨提取物进行直接解离CsCl密度梯度离心获得的低密度软骨蛋白制剂中。
