Hering T M, Kollar J, Huynh T D
Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4946, USA.
Arch Biochem Biophys. 1997 Sep 15;345(2):259-70. doi: 10.1006/abbi.1997.0261.
The previously available sequence for bovine aggrecan included only the KS domain, the C-terminal portion of the CS-2 domain, and the entire CS-3 and G3 domains. We have isolated cDNA clones for previously uncharacterized portions of the bovine aggrecan sequence, and, when we combined them with previously published incomplete sequences, have obtained a complete sequence for the entire core protein. The bovine aggrecan sequence, which is a composite of new sequence data and previously published incomplete sequences, is 2327 residues in length. Although there is significant conservation of G1, G2, and G3 globular domains between species, there are differences in the length of the interglobular domain, in the number of KS domain hexapeptide repeats and CS domain repeats, and in alternative splicing within the G3 domain. The bovine aggrecan KS domain contains 24 repeats of a hexapeptide motif. The largely uncharacterized CS-1 domain of bovine aggrecan was found to contain 27 variable repeats of a 21-residue consensus sequence. A notable feature of the bovine CS-1 domain is in the distribution of single Ser-Gly dipeptides, the majority of which are separated by 7 or 8 amino acids, compared to the human, where discrete pairs of Ser-Gly dipeptides are separated by 13 amino acids. The CS-2 domain contains a total of six "homology domains" with 4 complete and 2 partial approximately 100-residue repeats. Each "homology domain" contains a "nodal" region with few sites for CS chain addition that is highly conserved between species, suggesting a possible role in aggrecan biosynthesis or catabolism.
先前可得的牛聚集蛋白聚糖序列仅包括硫酸角质素（KS）结构域、硫酸软骨素-2（CS-2）结构域的C末端部分以及整个硫酸软骨素-3（CS-3）和G3结构域。我们已经分离出了牛聚集蛋白聚糖序列中先前未被表征部分的cDNA克隆，并且当我们将它们与先前发表的不完整序列相结合时，获得了整个核心蛋白的完整序列。牛聚集蛋白聚糖序列由新的序列数据和先前发表的不完整序列组成，长度为2327个残基。尽管物种之间G1、G2和G3球状结构域有显著的保守性，但球状结构域之间区域的长度、KS结构域六肽重复序列和CS结构域重复序列的数量以及G3结构域内的可变剪接存在差异。牛聚集蛋白聚糖的KS结构域包含24个六肽基序的重复序列。发现牛聚集蛋白聚糖中很大程度上未被表征的CS-1结构域包含27个21个残基共有序列的可变重复序列。牛CS-1结构域的一个显著特征是单个丝氨酸-甘氨酸二肽的分布，其中大多数被7或8个氨基酸隔开，而在人类中，离散的丝氨酸-甘氨酸二肽对被13个氨基酸隔开。CS-2结构域总共包含六个“同源结构域”，有4个完整的和2个部分的约100个残基的重复序列。每个“同源结构域”都包含一个“节点”区域，该区域几乎没有硫酸软骨素链添加位点，在物种之间高度保守，这表明其在聚集蛋白聚糖生物合成或分解代谢中可能发挥作用。
