STRUCTURAL AND FUNCTIONAL DOMAINS OF OSTEOPONTIN
STRUCTURAL AND FUNCTIONAL DOMAINS OF OSTEOPONTIN
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DOI：
10.1111/j.1749-6632.1995.tb44615.x
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发表时间：
1995-01-01
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影响因子：
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通讯作者：
BUTLER, WT
中科院分区：
文献类型：
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作者：
BUTLER, WT
骨桥蛋白 (OPN) 最初被描述为一种由转化细胞分泌的磷酸化蛋白质，而非非转化细胞分泌的磷酸化蛋白质。自这一初步观察以来，OPN 已在利用各种组织、细胞和生物液体的许多独立研究中被重新发现^.^-^ 在过去的十年中，关于 OPN 的发生和生物学相关性已经取得了显着的进展。在这篇评论中，我将尝试简要概述 OPN 结构的已知信息，以及该信息的哪些某些方面可以告诉我们有关其功能的信息。 OPN可以描述为一种富含唾液酸的磷酸化糖蛋白。它由 264 至 301 个氨基酸（取决于物种）的单链组成，富含天冬氨酸、谷氨酸和丝氨酸。迄今为止，大鼠骨 OPN 的特征最为明确；它含有约 30 个单糖，可能以 1 个 N 连接寡糖和 5-6 个 0 连接寡糖的形式存在。 6 该 OPN 还含有 12 个磷酸丝氨酸和 1 个磷酸苏氨酸，如 p-消除实验后对释放的磷酸盐和丢失的丝氨酸的仔细定量所示。 6 另据报道，大鼠 OPN 含有硫酸盐，但该取代基的性质尚未阐明。“大鼠、E 小鼠、9 人、I0 猪、牛、12 和鸡 I3 OPN 的完整氨基酸序列已从 cDNA 序列中推导出来。大约一半的大鼠序列通过 OPN 或其蛋白水解产物的测序得到验证^.^.'^ 同样，牛 OPN 的很大一部分已被测序并验证了推导的序列。
Osteopontin (OPN) was first described as a phosphorylated protein secreted by transformed cells but not by their nontransformed counterparts. Since this initial observation, OPN has been rediscovered in a number of independent studies utilizing a variety of tissues, cells and biological fluid^.^-^ During the past decade a remarkable amount of progress has been made concerning the occurrence and biological relevance of OPN. In this review I shall attempt to give a succinct overview of what is known about the structure of OPN and what certain aspects of this information can tell us about its function. OPN can be described as a phosphorylated glycoprotein that is rich in sialic acid. It consists of a single chain of 264 to 301 amino acids (depending upon the species) and is rich in aspartic acid, glutamic acid and serine. Rat bone OPN is the best characterized to date; it contains about 30 monosaccharides, potentially present as 1 N-linked and 5-6 0-linked oligosaccharides. 6 This OPN also contains 12 phosphoserines and 1 phosphothreonine, as shown by careful quantitation of the phosphate liberated and the serine lost, after p-elimination experiments. 6 It has also been reported that rat OPN contains sulfate, but the nature of this substituent was not clarified.'The complete amino acid sequences for rat, E mouse, 9 human, I0 pig," cow, 12 and chickenI3 OPN have been deduced from cDNA sequences. About half of the rat sequence was verified by sequencing of OPN or its proteolytic product^.^.'^ Likewise, a substantial portion of cow OPN has been sequenced and verifies the deduced sequence. 15