Calcitic biomineralization and matrix proteins

生物矿物的蛋白质成分（基质蛋白质）通过调节晶体成核和生长来影响最终结构的形状和强度，这反过来又定义了强烈影响机械性能的纹理特性和晶体形状。然而，实施这一规定的具体机制仍不清楚。我的研究项目利用一个新的模型系统来研究蛋白质如何影响钙化。鸟类蛋壳是已知的最快的钙化过程之一；在每天的鸡蛋形成过程中，6克矿物质在不到20小时的时间内沉积下来。这种钙质生物陶瓷是在脱细胞子宫液中形成的，在这种环境中，离子和蛋白质组成在矿物沉积的起始、快速钙化和终止阶段发生变化。这一过程的完整性对所有鸟类的繁殖都至关重要，因为蛋壳除了调节水和代谢气体的扩散外，还是抵御外部环境的物理和微生物屏障，并为生长中的胚胎提供钙的来源。蛋壳制作的缺陷已成为食品安全问题，据信，加拿大每年约有1万例因蛋壳破裂而导致沙门氏菌中毒。本应用程序的目的是支持研究，将提供洞察蛋壳基质蛋白如何调节方解石结晶模式。

The protein components of biominerals (matrix proteins) influence the shape and strength of the final structure by modulating crystal nucleation and growth, which in turn defines the textural properties and crystal shape that strongly affect mechanical performance. However, the specific mechanisms through which this regulation is exercised remain unclear. My research program utilizes a novel model system to investigate how proteins influence calcification. The avian eggshell is one of the fastest calcifying processes known; 6 g of mineral is deposited in less than 20 hr during the daily formation of the chicken egg. This calcitic bioceramic is formed in the acellular uterine fluid, a milieu in which the ionic and protein composition varies during the initiation, rapid calcification and termination phases of mineral deposition. The integrity of this process is vital for the propagation of all avian species, since the eggshell is a physical and microbial barrier against the external environment in addition to regulating diffusion of water and metabolic gases, and providing a source of calcium to the growing embryo. Flaws in eggshell fabrication become a food safety issue, and are believed to be responsible for about 10,000 cases of salmonella poisoning due to cracked eggshells annually in Canada. The objectives of this application are to support research that will provide insight into how eggshell matrix proteins regulate calcite crystallization patterns.