PZ – Nanobodies for multilevel examination of SLC26 transporters

抗体是检测和操作蛋白质不可缺少的研究工具。然而，目前还没有针对SLC26蛋白具有所需特异性和亲和力的高质量抗体。这是许多膜蛋白的典型情况，被认为是蛋白质稳定性差的直接后果，嵌入亲脂膜及其紧凑的尺寸，仅为常规抗体提供有限的潜在表位。纳米小体是骆驼类单结构域抗体的可变结构域，它为靶向膜蛋白的传统抗体提供了一种有前途的替代方案。纳米小体是一种很小但功能齐全的抗原结合片段，在大肠杆菌中很容易被生产更新。由于一个特别长的超变环，纳米体可以结合到蛋白质腔中，例如SLC26载体的结合裂缝。因此，纳米体非常适合在功能和结构研究中对这些转运蛋白进行功能抑制或抑制，或用作治疗药物。此外，与传统抗体相比，它们的小尺寸可以更好地穿透组织。我们将针对该研究单元研究的所有SLC26异构体生成纳米体，并根据每个单独项目的具体需求进行定制。纳米体针对溶质载体（如SLC26蛋白）的独特能力，加上其应用中的高通用性，使其成为实现本研究单元从结构测定和蛋白质复合物分离到细胞定位研究等多种目标的理想研究工具，并为开发治疗方法开辟了道路。

Antibodies are indispensable research tools for the detection and manipulation of proteins. However, high quality antibodies with the desired specificity and affinity for SLC26 proteins are currently not available. This is typical for many membrane proteins and is thought to be a direct consequence of poor protein stability, the embedding in lipophilic membrane and their compact size, providing only limited potential epitopes for conventional antibodies. Nanobodies, the variable domain of single-domain antibodies from camelids, offer a promising and proven alternative to conventional antibodies for targeting membrane proteins. Nanobodies are small but fully functional antigen binding fragments that are easily renewed by production in E. coli. Due to a particularly long hypervariable loop, nanobodies can bind into protein cavities, such as the binding clefts in SLC26 carriers. As a result, nanobodies are highly suited to functionally arrest or inhibit these transport proteins for functional and structural studies or use as therapeutics. Furthermore, their small size results in a much better tissue penetration compared to conventional antibodies. We will generate nanobodies against all SLC26 isoform studied in this Research Unit and tailored towards the specific needs of each individual project. The unique ability of nanobodies to target solute carriers, such as the SLC26 proteins, combined with the high versatility in their applications makes them ideal research tools for reaching the versatile goals of this Research Unit ranging from structure determination and protein complex isolation to cellular localization studies and opens the path towards developing therapeutics.