Biomaterials Group, Material Measurement Laboratory, NIST , 100 Bureau Drive, Gaithersburg, Maryland 20899-8543, United States.
Biomacromolecules. 2013 Oct 14;14(10):3417-22. doi: 10.1021/bm400660a. Epub 2013 Sep 10.
Acidic proteins are critical to biomineral formation, although their precise mechanistic function remains poorly understood. A number of recent studies have suggested a nonclassical mineralization model that emphasizes the importance of the formation of polymer-stabilized mineral clusters or particles; however, it has been difficult to characterize the precursors experimentally due to their transient nature. Here, we successfully captured stepwise evolution of transient CaP clusters in mineralizing solutions and studied the roles of functional polymers with laser light scattering (LLS) to determine how these polymers influence the stability of nanoclusters. We found that the polymer structure can alter CaP aggregation mechanisms, whereas the polymer concentration strongly influences the rate of CaP aggregation. Our results indicate that the ability of acidic biomolecules to control the formation of relatively stable nanoclusters in the early stages may be critical for intrafibrillar mineralization. More importantly, LLS provided information about the size and the structural evolution of CaP aggregates, which will help define the process of controlled biomineralization.
酸性蛋白对生物矿化的形成至关重要，尽管其确切的机制功能仍知之甚少。最近的许多研究提出了一种非经典的矿化模型，强调了聚合物稳定的矿化团簇或颗粒形成的重要性；然而，由于其瞬态性质，很难通过实验来表征前体。在这里，我们成功地捕获了矿化溶液中瞬态 CaP 团簇的分步演化，并通过激光光散射 (LLS) 研究了功能聚合物的作用，以确定这些聚合物如何影响纳米团簇的稳定性。我们发现聚合物结构可以改变 CaP 聚集机制，而聚合物浓度强烈影响 CaP 聚集的速度。我们的结果表明，酸性生物分子控制相对稳定的纳米团簇在早期形成的能力对于纤维内矿化可能至关重要。更重要的是，LLS 提供了有关 CaP 聚集体大小和结构演化的信息，这将有助于定义受控生物矿化的过程。
