Pokharna H K, Pottenger L A
Section of Orthopedic Surgery, University of Chicago Medical Center, IL 60637, USA.
Glycoconj J. 1997 Dec;14(8):917-23. doi: 10.1023/a:1018514727213.
In this study we have investigated whether proteoglycans (aggrecan) are modified by nonenzymatic glycation as in collagen. Purified human aggrecan from osteoarthritic and normal human knee articular cartilage was assayed for pentosidine, a cross-link formed by nonenzymatic glycation, using reverse-phase HPLC. In addition, an in vitro study was done by incubation of purified bovine nasal cartilage aggrecan with ribose. Pentosidine was found in all the purified human aggrecan samples. 2-3% of the total articular cartilage pentosidine was found in aggrecan. Purified link protein also contained penosidine. The in vitro study led to pentosidine formation, but did not appear to increase the molecular size of the aggrecan suggesting that pentosidine was creating intramolecular cross-links. Similar amounts of glycation were found in osteoarthritic and normal cartilage. Like collagen, aggrecan and link proteins are crosslinked by nonenzymatic glycation in normal and osteoarthritic cartilage. Crosslinking could be reproduced, in vitro, by incubating aggrecan with ribose.
在本研究中，我们调查了蛋白聚糖（聚集蛋白聚糖）是否如胶原蛋白那样被非酶糖基化修饰。使用反相高效液相色谱法，对从骨关节炎患者和正常人膝关节软骨中纯化得到的人聚集蛋白聚糖进行了检测，以测定戊糖苷（一种由非酶糖基化形成的交联物）。此外，通过将纯化的牛鼻软骨聚集蛋白聚糖与核糖一起孵育进行了一项体外研究。在所有纯化的人聚集蛋白聚糖样品中均发现了戊糖苷。在聚集蛋白聚糖中发现了占关节软骨总戊糖苷2 - 3%的量。纯化的连接蛋白中也含有戊糖苷。体外研究导致了戊糖苷的形成，但似乎并未增加聚集蛋白聚糖的分子大小，这表明戊糖苷正在形成分子内交联。在骨关节炎软骨和正常软骨中发现了相似量的糖基化。与胶原蛋白一样，在正常和骨关节炎软骨中，聚集蛋白聚糖和连接蛋白都通过非酶糖基化发生交联。通过在体外将聚集蛋白聚糖与核糖一起孵育，可以重现交联过程。
