Termine J D, Kleinman H K, Whitson S W, Conn K M, McGarvey M L, Martin G R
Cell. 1981 Oct;26(1 Pt 1):99-105. doi: 10.1016/0092-8674(81)90037-4.
Osteonectin is a 32,000 dalton bone-specific protein that binds selectively to both hydroxyapatite and collagen. When osteonectin is bound to insolubilized type I collagen, the resultant complex binds synthetic apatite crystals and free calcium ions. The osteonectin-collagen complexes also nucleate mineral phase deposition from metastable balanced salt solutions, Antibodies to osteonectin cross-react with bone and, to a lesser extent, dentin, but not with other tissues. The protein is localized to mineralized bone trabeculae and occurs at higher levels in the matrix than in the cells of bone. These studies suggest that osteonectin is a tissue-specific protein, linking the bone mineral and collagen phases, perhaps initiating active mineralization in normal skeletal tissue.
骨连接素是一种分子量为32,000道尔顿的骨特异性蛋白，它能选择性地与羟基磷灰石和胶原蛋白结合。当骨连接素与不溶性I型胶原蛋白结合时，形成的复合物会结合合成磷灰石晶体和游离钙离子。骨连接素-胶原蛋白复合物还能使亚稳态平衡盐溶液中的矿质相沉积成核。抗骨连接素抗体与骨发生交叉反应，与牙本质的交叉反应较弱，但与其他组织无交叉反应。该蛋白定位于矿化的骨小梁，在基质中的含量高于骨细胞。这些研究表明，骨连接素是一种组织特异性蛋白，连接骨矿物质和胶原蛋白阶段，可能在正常骨骼组织中启动活性矿化。
