2026/06/13 by Maximilian H. Ganser, Markus Wiederstein, Christof Regl +2 · 1 voice · 1 citation
Biochemistry, Genetics and Molecular Biology · Environmental Science · Materials Science · #Protist diversity and phylogeny #Bacteriophages and microbial interactions #Supramolecular Self-Assembly in Materials
paper · pdf · doi:10.1038/s41467-026-74402-4
Biomaterials provide superior properties and sustainable alternatives relevant to medicine, textiles, and high-tech applications. Research has mainly focused on animal-derived proteinaceous biomaterials, which remain challenging to reproduce while retaining their remarkable properties. Here, we show that the shell biomaterial of tintinnid ciliates, a lineage of planktonic unicellular eukaryotes, is composed of self-assembling structural proteins. The shells form in sea- and freshwater, are structurally diverse, and exhibit resistance against high temperatures and the strongest chemicals. Combining single-cell transcriptomics with proteomics of the shells, we identify the amino acid sequences of the shell-forming proteins that represent a new family unique to tintinnid ciliates, which we term Tintinnidorin. The proteins are rich in aromatic residues and possess a coherent architecture with flexible, unfolded segments connecting a folded core structure of beta-sheets. These multivalent capabilities facilitate intracellular storage, extracellular self-assembly, wet adhesion, thermostability, and salt tolerance. Tintinnid ciliates and their Tintinnidorin proteins provide an accessible system to elucidate sequence-structure-material relationships and inspire biomaterial design.