Völkle Nee Evgrafov Elke, Schulz Fabian, Kanold Julia Maxi, Michaelis Monika, Wissel Kerstin, Brümmer Franz, Schenk Anna S, Ludwigs Sabine, Bill Joachim, Rothenstein Dirk
Dept. Bioinspired Materials, Institute for Materials Science, University of Stuttgart, Heisenbergstraße 3, 70569 Stuttgart, Germany.
Institute for Biomaterials and Biomolecular Systems & Scientific Diving Group (WiTUS), University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany.
J Mater Chem B. 2023 Nov 1;11(42):10174-10188. doi: 10.1039/d3tb01584j.
The intricate process of biomineralization, in sea urchins, involves the precise interplay of highly regulated mineralization proteins and the spatiotemporal coordination achieved through compartmentalization. However, the investigation of biomineralization effector molecules, proteins, is challenging, due to their very low abundance. Therefore, we investigate the functional mimicry in the bioinspired precipitation of calcium carbonate (CaCO) with artificial peptides selected from a peptide library by phage display based on peptide-binding to calcite and aragonite, respectively. The structure-directing effects of the identified peptides were compared to those of natural protein mixes isolated from skeletal (test) structures of two sea urchin species ( and ). The calcium carbonate samples deposited in the absence or presence of peptides were analyzed with a set of complementary techniques with regard to morphology, polymorph, and nanostructural motifs. Remarkably, some of the CaCO-binding peptides induced morphological features in calcite that appeared similar to those obtained in the presence of the natural protein mixes. Many of the peptides identified as most effective in exerting a structure-directing effect on calcium carbonate crystallization were rich in basic amino acid residues. Hence, our mineralization study further highlights the important, but often neglected, role of positively charged soluble organic matrices associated with biological and bioinspired CaCO deposition.
海胆体内复杂的生物矿化过程涉及高度调控的矿化蛋白之间精确的相互作用，以及通过区室化实现的时空协调。然而，对生物矿化效应分子（即蛋白质）的研究颇具挑战性，因为它们的丰度极低。因此，我们基于分别与方解石和文石结合的肽，通过噬菌体展示从肽库中选择人工肽，研究其在碳酸钙（CaCO₃）仿生沉淀中的功能模拟。将鉴定出的肽的结构导向效应与从两种海胆（和）的骨骼（测试）结构中分离出的天然蛋白质混合物的结构导向效应进行比较。使用一套互补技术，对在有无肽存在的情况下沉积的碳酸钙样品的形态、多晶型和纳米结构基序进行分析。值得注意的是，一些与CaCO₃结合的肽在方解石中诱导出的形态特征，与在天然蛋白质混合物存在时所获得的形态特征相似。许多被鉴定为对碳酸钙结晶具有最有效结构导向作用的肽富含碱性氨基酸残基。因此，我们的矿化研究进一步凸显了带正电荷的可溶性有机基质在生物和仿生CaCO₃沉积中所起的重要但常被忽视的作用。
