Mineral deposition in biological systems is often templated by organic matrices including proteins directing the nucleation and growth of bioceramics by interacting with early stage species of the mineralization process or coordinating specific facets of the forming crystal. Structurally, charged surface patches are a characteristic motif of biomineralization-associated proteins, which are able to accumulate and bind ions from the surrounding media and, therefore, initiate, promote or inhibit mineralization. Controlled protein engineering enables the manipulation and control of bioinspired in vitro precipitation systems, and thus not only opens prospects for the design of environmentally benign synthetic strategies towards hierarchically structured functional materials, but also enhances the understanding of fundamental interaction mechanisms in biomineralization processes. Here, two recombinant variants of the spider silk protein ADF4 were engineered with oppositely charged peptide tags. Both were processed into micrometer-sized particles and investigated for their influence on manganese carbonate mineralization. Micro- and nano-structured manganese carbonate represents an attractive material for diverse applications including catalysis and wastewater treatment. While both types of spider silk particles were incorporated into the mineral structure, the positively tagged proteins appeared to interact more strongly with the formed manganese carbonate crystals than their negatively charged counterparts. Combination of the spider silk particles and poly(acrylic acid) (PAA), a water-soluble structure-directing agent associated with the stabilization of amorphous precursor phases in carbonates, resulted in the formation of film-like non-equilibrium structures of MnCO₃ entrapping the spider silk particles. With the aim to gain mechanistic insights and to elucidate the interaction between the different components involved in the mineralization process, we studied the interplay between PAA, positively or negatively tagged spider silk particles, and Mn(II) ions by time-resolved dynamic light scattering. The here used set-up affords the possibility to identify control strategies for the template-mediated mineralization of manganese carbonate.

生物系统中的矿物沉积通常以有机基质为模板，包括通过与矿化过程的早期物种相互作用或协调形成晶体的特定方面来指导生物陶瓷的成核和生长的蛋白质。从结构上讲，带电表面斑块是生物矿化相关蛋白的特征基序，它能够从周围介质中积累和结合离子，从而启动、促进或抑制矿化。受控蛋白质工程能够在体外操作和控制生物启发沉淀系统，因此不仅为设计具有层次结构的功能材料的环境良性合成策略开辟了前景，而且还增强了对生物矿化过程中基本相互作用机制的理解。在这里，蜘蛛丝蛋白 ADF4 的两个重组变体被设计成带有相反电荷的肽标签。两者都被加工成微米大小的颗粒，并研究它们对碳酸锰矿化的影响。微米和纳米结构的碳酸锰代表了一种具有吸引力的材料，可用于多种应用，包括催化和废水处理。虽然两种类型的蜘蛛丝颗粒都融入了矿物结构中，与带负电的对应物相比，带正标签的蛋白质似乎与形成的碳酸锰晶体的相互作用更强。蜘蛛丝颗粒和聚（丙烯酸）（PAA）（一种与碳酸盐中无定形前体相稳定相关的水溶性结构导向剂）的组合导致形成薄膜状 MnCO 非平衡结构₃捕获蜘蛛丝颗粒。为了获得机理见解并阐明矿化过程中不同组分之间的相互作用，我们通过时间分辨动态光散射研究了 PAA、带正标签或负标签的蜘蛛丝颗粒和 Mn(II) 离子之间的相互作用. 这里使用的设置提供了确定模板介导的碳酸锰矿化控制策略的可能性。