INHIBITION OF HYDROXYAPATITE CRYSTAL-GROWTH BY BONE-SPECIFIC AND OTHER CALCIUM-BINDING PROTEINS
INHIBITION OF HYDROXYAPATITE CRYSTAL-GROWTH BY BONE-SPECIFIC AND OTHER CALCIUM-BINDING PROTEINS
复制标题
DOI：
10.1021/bi00353a035
复制
发表时间：
1986-03-11
期刊：
影响因子：
2.9
通讯作者：
MANN, KG
中科院分区：
文献类型：
--
作者：
ROMBERG, RW;WERNESS, PG;MANN, KG
骨基质的矿化可能受到特定的非胶原性骨蛋白的影响。两种骨特异性蛋白sbd.骨γ-的定量影响羧基谷氨酸（Gla）蛋白质和骨连接蛋白sbd以及降低晶体生长速率的其它蛋白质的含量是通过在37 ℃下将羟基磷灰石的晶种加入到CaCl 2和KH 2 PO 14的溶液（pH 7.4）中来测量的。C.抑制50%晶体生长速率所需的蛋白质的摩尔浓度如下：骨粘连蛋白，0.15 μ M;骨Gla蛋白，0.8 μ M;凝血酶原，0.9 μ M;凝血酶原片段1，1.0 μ M;大豆胰蛋白酶抑制剂，3 μ M;凝血酶原1，9 μ M;细胞色素c，30 μ M。钙调素和小清蛋白被发现是活性低于凝血酶原片段1，并没有在微摩尔范围内的活动。两种抑制剂的组合产生具有抑制活性的混合物，该抑制活性是两种抑制剂的总和。骨Gla蛋白的脱羧显著降低其抑制活性。这些结果表明，在这些条件下，蛋白质的抑制活性与Ca 2+结合亲和力不相关，抑制剂的混合物具有累加效应，并且γ-羧基谷氨酸残基增强蛋白质抑制羟基磷灰石晶种晶体生长的能力。
Mineralization of bone matrix may be influenced by the presence of specific, noncollagenous bone proteins. The quantitative influence of two bone-specific proteins.sbd.bone .gamma.-carboxyglutamic acid (Gla) protein and osteonectin.sbd.and other proteins that decreased the rate of crystal growth was measured by adding seed crystals of hydroxyapatite to a solution of CaCl2 and KH2PO14, pH 7.4 at 37.degree. C. The molar concentrations of proteins needed to inhibit the rate of crystal growth by 50% were as follows: osteonectin, 0.15 .mu.M; bone Gla protein, 0.8 .mu.M; prothrombin, 0.9 .mu.M; prothrombin framgment 1, 1.0 .mu.M; soybean trypsin inhibitor, 3 .mu.M; prethrombin 1, 9 .mu.M; cytochrome c, 30 .mu.M. Calmodulin and parvalbumin were found to be less active than prothrombin fragment 1 and had no activity in the micromolar range. The combination of two inhibitors resulted in a mixture with an inhibitory activity that was the sum of the two inhibitors. Decarboxylation of bone Gla protein significantly reduced its inhibitory activity. These results indicate that the inhibitory activity of a protein does not correlate with Ca2+-binding affinity under these conditions, that the mixture of inhibitors has an additive effect, and that .gamma.-carboxyglutamic acid residues enhance the ability of a protein to inhibit hydroxyapatite-seeded crystal growth.