Development of a new radioimmunoassay for human osteocalcin: evidence for a midmolecule epitope.
Development of a new radioimmunoassay for human osteocalcin: evidence for a midmolecule epitope.
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开发一种新的人骨钙素放射免疫测定法：中分子表位的证据。
DOI：
10.1016/0026-0495(88)90122-9
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Baylink,DJ
中科院分区：
文献类型：
--
作者：
Taylor,AK;Linkhart,SG;Mohan,S;Baylink,DJ
骨钙素是一种维生素 K 依赖性骨特异性蛋白，可在血清中循环。骨钙素的循环水平已被证明是骨转换的指标。现有的骨钙素放射免疫测定法已被证明对 C 末端表位具有特异性，该区域在人和牛骨钙素中是相同的。然而，该分子的 N 末端区域有 5 个不同的氨基酸。我们在此描述了使用从人股骨头骨粉中纯化的骨钙素对骨钙素的中分子表位进行免疫测定。使用胰蛋白酶消化物和人骨钙素的合成片段确定抗体特异性。该测定与牛骨钙素仅具有部分交叉反应性。这是针对骨钙素分子中表位的检测的第一份报告，涉及人类骨钙素和牛骨钙素不同的区域。通过该测定测定的骨钙素水平与正常成人血清中的总血清碱性磷酸酶和血清骨骼碱性磷酸酶水平显着相关，并且在更大程度上与患有骨转换增加相关疾病（佩吉特病、甲状旁腺功能亢进和新生儿血清）的患者血清中显着相关。这些相关性比之前报道的 C 末端测定的相关性更大，表明分子的不同区域可能会引发有关骨转换的不同信息。
Osteocalcin is a vitamin K-dependent bone-specific protein that can be found circulating in the serum. The circulating levels of osteocalcin have been shown to be an index of bone turnover. Existing radioimmunoassays for osteocalcin have been shown to be specific for C-terminal epitopes, a region that is identical in the human and bovine osteocalcin. There are, however, five amino acids different in the N-terminal region of the molecule. We describe here an immunoassay for a midmolecule epitope of osteocalcin using osteocalcin purified from human femoral head bone powder. Antibody specificity was determined using tryptic digests and a synthetic fragment of human osteocalcin. This assay has only a partial crossreactivity with bovine osteocalcin. This is the first report of an assay against a midmolecular epitope of osteocalcin involving a region in which the human and bovine osteocalcins differ. Osteocalcin levels determined by this assay have a significant correlation with both the total serum alkaline phosphatase and the serum skeletal alkaline phosphatase levels in normal adult human serum and, to a greater degree, in sera of patients with conditions associated with increased bone turnover (Paget's disease, hyperparathyroidism, and newborn sera). These correlations are greater than those previously reported for C-terminal assays, suggesting the possibility that different regions of the molecule may elicit different information concerning bone turnover.