Dental enamel forms through a protein-controlled mineralization and enzymatic degradation with a nanoscale precision that new engineering technologies may be able to mimic. Recombinant full-length human amelogenin (rH174) and a matrix-metalloprotease (MMP-20) were employed in a pH-stat titration system that enabled a continuous supply of calcium and phosphate ions over several days, mimicking the initial stages of matrix processing and crystallization in enamel in-vitro. Effects on the self-assembly and crystal growth from a saturated aqueous solution containing 0.4 mg/ml rH174 and MMP-20 with the weight ratio of 1:1000 with respect to rH174 were investigated. A transition from nanospheres to fibrous amelogenin assemblies was facilitated under conditions that involved an interaction between rH174 and the proteolytic cleavage products. Despite continuous titration, the levels of calcium exhibited a consistent trend of decreasing, thereby indicating its possible role in the protein self-assembly. This study suggests that mimicking enamel formation in-vitro requires the synergy between the aspects of matrix self-assembly, proteolysis and crystallization.
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机译：牙釉质是通过蛋白质控制的矿化作用和酶促降解形成的，具有纳米级的精度，新的工程技术可以模仿这种釉质。重组全长人牙釉蛋白（rH174）和基质金属蛋白酶（MMP-20）用于pH稳定滴定系统，该系统能够在几天内连续供应钙离子和磷酸根离子，从而模仿了基质加工的初始阶段。在体外搪瓷中结晶。研究了相对于rH174，从0.4 mg / ml rH174和MMP-20的饱和水溶液（重量比为1：1000）对自组装和晶体生长的影响。在涉及rH174和蛋白水解裂解产物相互作用的条件下，促进了从纳米球到纤维状黄原蛋白组装体的转变。尽管进行了连续滴定，钙的含量仍呈现出持续下降的趋势，从而表明了钙在蛋白质自组装中的可能作用。这项研究表明，体外模拟牙釉质的形成需要基质自组装，蛋白水解和结晶之间的协同作用。
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