Structural adaptability and surface activity of peptides derived from tardigrade proteins

作者：G. Giubertoni, Sarah Chagri, Pablo G. Argudo, Leon Prädel, Daria Maltseva, Alessandro Greco, F. Caporaletti, Alberto Pavan, I. Ilie, Yong Ren, David Y W Ng, Mischa Bonn, Tanja Weil, S. Woutersen · 发表于：Protein Science · 年份：2024 · DOI：10.1002/pro.5135 · 被引用次数：3 · 研究领域：Medicine

Tardigrades are unique micro‐organisms with a high tolerance to desiccation. The protection of their cells against desiccation involves tardigrade‐specific proteins, which include the so‐called cytoplasmic abundant heat soluble (CAHS) proteins. As a first step towards the design of peptides capable of mimicking the cytoprotective properties of CAHS proteins, we have synthesized several model peptides with sequences selected from conserved CAHS motifs and investigated to what extent they exhibit the desiccation‐induced structural changes of the full‐length proteins. Using circular dichroism spectroscopy, two‐dimensional infrared spectroscopy, and molecular dynamics simulations, we have found that the CAHS model peptides are mostly disordered, but adopt a more α$$ \alpha $$ ‐helical structure upon addition of 2,2,2‐trifluoroethanol, which mimics desiccation. This structural behavior is similar to that of full‐length CAHS proteins, which also adopt more ordered conformations upon desiccation. We also have investigated the surface activity of the peptides at the air/water interface, which also mimics partial desiccation. Interestingly, sum‐frequency generation spectroscopy shows that all model peptides are surface active and adopt a helical structure at the air/water interface. Our results suggest that amino acids with high helix‐forming propensities might contribute to the propensity of these peptides to adopt a helical structure when fully or partially dehydrated. Thus, the sel...