Model Studies on the Function of Acidic Proteins in Biomineralization

导致各种生物矿物结构的生物过程在很大程度上尚未解决。根据广泛接受的模板基质假说，钙化组织（如骨骼、软体动物壳）的有机基质确实含有特定的大分子，这些大分子可以促进或抑制晶体的选择性成核，并指导过度生长的晶体层的空间取向。由于目前关于天然基质大分子的三维结构的信息非常有限，我们正在开发合成大分子（例如两亲性杯芳烃羧酸和高酸性肽），这些大分子是专门设计的，例如模拟生物系统假定功能的关键方面。天然表面活性酸性蛋白的基本结构特性（即结合表位包括固定在两亲性b-褶片，螺旋或环上的羧酸残基阵列）被人工肽模仿。阐明人工蛋白对无机晶体相（方解石、文石、水晶石）在适当的模型系统中生长的影响是我们研究的主要重点，为此，我们在灌注装置中采用单层和固定化薄膜。

The biological processes which lead to a wide variety of biomineral structures are largely unsolved. According to the widely accepted template-matrix-hypothesis , the organic matrix of calcified tissues (e.g. bones, mollusc shells) does contain specific macromolecules, which promote or inhibit the site-selective nucleation of crystals, and which direct the spatial orientation(s) of the overgrowing crystal layer. Owing to the very limited information which is currently available about the 3D structures of the natural matrix macromolecules, we are developing synthetic macromolecules (e.g. amphiphilic calixarene carboxylic acids and highly acidic peptides), which are specifically designed such as to mimic crucial aspects of the putative function of the biological systems. Essential structural properties of natural surface-active acidic proteins (i.e. binding epitopes comprising arrays of carboxylic acid residues fixed to amphiphilic b-pleated sheets, helices or loops) are imitated by artificial peptides. Elucidating the influence of the artificial proteins on the growth of inorganic crystal phases (calcite, aragonite, vaterite) within the appropriate model system is a main focus of our research, for which we employ monolayers and immobilized thin films in a perfusion device.