Catabolism of aggrecan by explant cultures of human articular cartilage in the presence of retinoic acid.
Catabolism of aggrecan by explant cultures of human articular cartilage in the presence of retinoic acid.
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在视黄酸存在下通过人关节软骨的外植体培养物进行聚集蛋白聚糖的分解代谢。
DOI：
10.1006/abbi.1995.1431
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Handley,CJ
中科院分区：
文献类型：
--
作者：
Ilic,MZ;Mok,MT;Williamson,OD;Campbell,MA;Hughes,CE;Handley,CJ
测定了人聚集蛋白聚糖的N-末端氨基酸序列，结果显示存在两个序列。主要序列AVTVE-占聚集蛋白聚糖的60％并且起始于人聚集蛋白聚糖核心蛋白cDNA序列的丙氨酸残基17(K.Doege等人(1991)J.Biol.Chem.266, 894-920)。另一个 N 端序列 VETX- 起始于缬氨酸残基 20。成人关节软骨基质中存在的聚集蛋白聚糖核心蛋白肽的表征表明，存在至少 11 个聚集蛋白聚糖核心蛋白，Mr 大约在 300,000 到 43,000 之间。发现所有这些核心蛋白都具有与人聚集蛋白聚糖中观察到的相同的 N 端序列。当将关节软骨置于含有 10−6M 视黄酸的培养基中的外植体培养物中时，与单独培养基或含有 20% (v/v) 新生小牛血清的培养基中维持的组织相比，培养基中聚集蛋白聚糖的损失增加了 3.5 倍。对释放到含有 10−6M 视黄酸的培养基中的聚集蛋白聚糖核心蛋白片段的分析显示，存在 300,000 至 43,000 之间的 13 个 Mr 核心蛋白肽。 Mr230,000 至 43,000 的 11 个较小肽显示出具有 N 端序列 ARGS-。该序列起始于人聚集蛋白聚糖核心蛋白的残基 393，位于 G1 和 G2 结构域之间的球间区域内，并且是假定的蛋白酶聚集蛋白聚糖酶进行聚集蛋白聚糖分解代谢的位点。不同大小但具有相同 N 端序列的核心蛋白的存在反映了核心蛋白 C 端的蛋白水解加工，这也在从人关节软骨基质中提取的聚集蛋白聚糖大分子中观察到。这种蛋白水解过程在新合成的 35 S 标记的聚集蛋白聚糖大分子中也很明显，但程度较小。
The N-terminal amino acid sequence of human aggrecan was determined and it was shown that two sequences were present. The major sequence, AVTVE-, accounted for 60% of the aggrecan and started at alanine residue 17 of the human aggrecan core protein cDNA sequence (K. Doege et al. (1991) J. Biol. Chem. 266, 894-920). The other N-terminal sequence, VETX-, started at valine residue 20. Characterization of aggrecan core protein peptides present in the matrix of adult human articular cartilage showed that at least 11 aggrecan core proteins were present with approximate Mrbetween 300,000 and 43,000. All these core proteins were found to have the same N-terminal sequences as that observed in human aggrecan. When articular cartilage was placed in explant culture in medium containing 10−6M retinoic acid there was a 3.5-fold increase in the loss of aggrecan into the culture medium compared to tissue maintained in medium alone or medium containing 20% (v/v) newborn calf serum. Analysis of the aggrecan core protein fragments that were released to the culture medium containing 10−6M retinoic acid showed the presence of 13 core protein peptides of Mrbetween 300,000 and 43,000. The 11 smaller peptides of Mr230,000 to 43,000 were shown to have the N-terminal sequence ARGS-. This sequence which starts at residue 393 of the human aggrecan core protein is located within the interglobular region between the G1 and G2 domains and is the site of aggrecan catabolism by the putative protease aggrecanase. The presence of core proteins of varying sizes but with the same N-terminal sequence reflects proteolytic processing from the C-terminal end of the core protein that was also observed in the aggrecan macromolecules extracted from the matrix of human articular cartilage. This proteolytic processing was also evident but to a lesser extent in newly synthesized35S-labeled aggrecan macromolecules.