SELECTIVE ADSORPTION OF PORCINE-AMELOGENINS ONTO HYDROXYAPATITE AND THEIR INHIBITORY ACTIVITY ON HYDROXYAPATITE GROWTH IN SUPERSATURATED SOLUTIONS
SELECTIVE ADSORPTION OF PORCINE-AMELOGENINS ONTO HYDROXYAPATITE AND THEIR INHIBITORY ACTIVITY ON HYDROXYAPATITE GROWTH IN SUPERSATURATED SOLUTIONS
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DOI：
10.1007/bf02555230
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发表时间：
1987-11-01
影响因子：
4.2
通讯作者：
MORENO, EC
中科院分区：
文献类型：
--
作者：
AOBA, T;FUKAE, M;MORENO, EC
研究了人工合成羟基磷灰石(HA)对釉原蛋白的选择性吸附及其对HA晶体生长的抑制作用。特别关注了原釉原蛋白(S)的分泌后降解对其吸附和抑制活性的影响。在吸附研究中，原来分泌的釉原蛋白(25K)、脯氨酸和富含组氨酸的蛋白(2a)以及较高的分子组成(60-90K)对HA显示出很强的吸附亲和力。这种对蛋白质2a的吸附与在稀溶液中抑制了晶种HA的晶体生长有关。另一方面，釉原蛋白的部分降解产物(20K)蛋白2b失去了对透明质酸的高吸附亲和力，因此没有显示出明显的抑制活性。在pH为6.0和7.4时，HA对蛋白质2a有明显的选择性吸附，但在pH为7.8或10.8时，这种选择性行为对pH的变化很敏感。结果表明，原来分泌的釉原蛋白2a可能在釉质形成中起积极作用，在完全去除之前，釉原蛋白的分泌和部分酶降解使其失活，从而调节釉质的矿化。
The selective adsorption of amelogenins onto synthetic hydroxyapatite (HA) and their inhibitory activity on the seeded HA crystal growth were investigated using enamel proteins obtained from the outer layer of immature porcine-enamel (soft, cheeselike in consistency) of developig permanent incisors. Special interests were paid to the effect of a postsecretory degradation of the original amelogenin(s) on their adsorption and inhibitory activity. In the adsorption studies, it was apparent that the originally secreted amelogenin (25 K), proline, and histidine-rich protein (2a), as well as the higher molecular components (60-90 K), showed a strong adsorption affinity onto the HA. This adsorption of protein 2a was related to the inhibition of the srystal growth of seeded HA in a dilute supersaturated solution. On the other hand, the partially degraded product (20 K) of amelogenins, protein 2b, lost the high adsorption affinity into the HA, and consequently showed no significant inhibitory activity. The observed selective adsorption of protein 2a onto HA was apparent at pH 6.0 and pH 7.4 even in the presence of dissociative solvents, such as 3 M urea of 2 and 4 M guanidine-HCl; however this selective behavior was sensitive to changes in pH, and was not displayed at pH values of 7.8 or 10.8. The results suggest that the originally secreted amelogenin 2a may play an active role in amelogenesis, and that enamel mineralization could be regulated by the secretion of amelogenins and their inactivation through partial enzymic degradation, prior to their complete removal.