MINERAL INDUCTION BY IMMOBILIZED POLYANIONIC PROTEINS
MINERAL INDUCTION BY IMMOBILIZED POLYANIONIC PROTEINS
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DOI：
10.1007/bf02553763
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发表时间：
1989-04-01
影响因子：
4.2
通讯作者：
CRENSHAW, MA
中科院分区：
文献类型：
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作者：
LINDE, A;LUSSI, A;CRENSHAW, MA
本研究的目的是研究共价结合在表面的聚阴离子蛋白在体外对矿物质的诱导能力。将大鼠牙本质-γ-羧基谷氨酸-骨钙素型蛋白(GLA-蛋白)、蛋白多糖(PG)和磷蛋白(PP-H)以及磷高磷蛋白(PHV)和牛血清白蛋白(BSA)共价连接到琼脂糖珠上。这些材料在37℃的Ca/P摩尔比为1.67的溶液中孵化。[C][P]摩尔产物为1.0mm2-1.8mm2，离子强度为0.165。孵化是在恒定的pH和组成条件下进行的，在这些条件下没有自发沉淀。扫描电子显微镜(SEM)观察到，所有固定化的聚阴离子，包括酶去磷酸化的PP-H和PHV，都能诱导矿物形成。BSA未诱导出矿物质。固定化多阴离子蛋白的矿物质诱导能力在不同的配体之间存在差异。X-射线衍射法表明，PP-H和PG诱导的矿物为磷灰石。结论是，尽管溶液中的多阴离子蛋白质可能抑制矿物质的诱导和生长，但当极少量的此类分子固定在表面时，在生理浓度的钙离子和磷酸盐离子下诱导矿物质生长。目前的数据可能表明PP-H和PG，也许还有其他多阴离子，可能是牙本质和骨骼中矿物质成核的原因。然而，结果也表明这种反应的特异度相当有限。
The purpose of this study was to investigate the mineral induction capacity in vitro of polyanionic proteins covalently bound to a surface. Rat dentin .gamma.-carboxyglutamate-containing protein of the osteocalcin type (Gla-protein), proteoglycan (PG), and phosphoprotein (PP-H), as well as phosvitin (PhV) and bovine serum albumin (BSA), were covalently linked to agarose beads. These were incubated at 37.degree.C in solutions with a Ca/P molar ratio of 1.67. [C][P] molar products in the range 1.0-1.8 mM2, and an ionic strength of 0.165. The incubations were performed at constant pH and composition conditions; no spontaneous precipitation occurred under these conditions. Mineral formation, as monitored by scanning electron microscopy (SEM), was induced by all immobilized polyanions, including enzymatically dephosphorylated PP-H and PhV. No mineral was induced by BSA. The mineral inductive capacity of immobilized polyanionic proteins, as judged by the SEM after identical incubations, was found to differ between the different ligands. The mineral induced by PP-H and PG was shown by X-ray diffraction to be apatitic. It was concluded that, although polyanionic proteins in solution may inhibit mineral induction and growth, very minute quantities of such molecules, when immobilized on a surface, induce mineral at physiological concentrations of calcium and phosphate ions. The data presented may be taken to suggest that PP-H and PG, and perhaps other polyanions, may possibly the responsible for mineral nucleation in dentin and bone. The results, however, also point to the rather limited specificity in this type of reaction.