Reconstitution of Mineral Morphogenesis in Membrane-enclosed Compartments

生物矿化通常发生在膜封闭的隔间中，其中矿物前体和辅助分子在有限体积中结合。矿物质前体向这些膜封闭的隔室的转移是通过与隔室膜融合的专门囊泡实现的。如何逐步转移的前体和释放到封闭的膜封闭的隔间发生，以及如何在隔间内的物理化学条件和矿化改性剂影响矿物的形态还没有得到很好的理解。为了获得这些参数，我们在这个项目中的目标是建立一个通用的体外系统，使我们能够（i）重建膜封闭的隔间，（ii）通过囊泡融合以逐步的方式添加矿物质形成化合物，以及（iii）定量研究矿化作为膜和隔间内部的化学和物理条件的函数。新的电机为基础的囊泡运输结合融合系统，我们的目标是建立旨在允许高度本地化的融合事件，并模仿自然囊泡室融合机器相信在生物矿化。在项目中，我们将重点关注矿物碳酸钙。我们将询问不同类型的矿物前体，有机矿化改性剂，离子和分子crowders的存在下，车厢内改变矿化的动力学以及最终mineral.Further，我们的目标是研究如何的大小和形状的车厢，以及封闭的脂质双层的组成影响矿物形态。除了有助于我们理解碳酸钙矿物形态发生，我们希望我们的方法将为其他矿物的研究提供基础。我们项目的总体目标是开发一个完全合成的系统，模仿生物矿化的自然多步骤过程。

Biomineralization often takes place in membrane-enclosed compartments, where mineral precursors and accessory molecules are combined in a finite volume. Transfer of the mineral precursors to these membrane-enclosed compartments is realized by specialized vesicles that fuse with the compartment membrane. How the stepwise transfer of precursors and release into the confined membrane-enclosed compartment occurs as well as how the physico-chemical conditions and mineralization modifiers within the compartment influence mineral morphogenesis is not well under-stood. To get access to these parameters, we aim in this project at establishing a versatile in vitro system that allows us to (i) reconstitute membrane-enclosed compartments, (ii) add mineral-forming compounds in a stepwise manner via fusion of vesicles, and (iii) quantitatively investigate mineralization as function of the chemical and physical conditions of the membrane and inside the compartment. The novel motor-based vesicle transport in conjunction with a fusion system that we aim to establish is intended to allow for highly-localized fusion events and to mimic the natural vesicle-compartment fusion machineries believed to operate in biomineralization. In the project, we will focus on the mineral calcium carbonate. We will ask how the presence of different types of mineral precursors, organic mineralization modifiers, ions and molecular crowders inside the compartments alter the kinetics of mineralization as well as the final mineral. Furthermore, we aim at studying how sizes and shapes of the compartments as well as the composition of the enclosing lipid bilayers influence mineral morphology. Beyond contributing to our understanding of calcium carbonate mineral morphogenesis, we expect that our approach will provide the basis for studies on other minerals. The overall goal of our project will be the development of a fully synthetic system mimicking the natural multi-step process of biomineralization.