Proton conductivity of the protein-based velvet worm slime.

The properties of complex bodily fluids are linked to their biological functions through natural selection. Velvet worms capture their prey by ensnaring them with a proteinaceous fluid (slime). We examined the electrical conductivity of slime and found that dry slime is an insulator.

Cephalopod-Mimetic Tunable Photonic Coatings Assembled from Quasi-Monodispersed Reflectin Protein Nanoparticles.

The remarkable dynamic camouflage ability of cephalopods arises from precisely orchestrated structural changes within their chromatophores and iridophores photonic cells. This mesmerizing color display remains unmatched in synthetic coatings and is regulated by swelling/deswelling of reflectin protein nanoparticles, which alters platelet dimensions in iridophores to control photonic patterns according to Bragg's law. Toward mimicking the photonic response of squid's skin, reflectin proteins from were sequenced, recombinantly expressed, and self-assembled into spherical nanoparticles by conjugating reflectin B1 with a click chemistry ligand.

A diecast mineralization process forms the tough mantis shrimp dactyl club.

Biomineralization, the process by which mineralized tissues grow and harden via biogenic mineral deposition, is a relatively lengthy process in many mineral-producing organisms, resulting in challenges to study the growth and biomineralization of complex hard mineralized tissues. Arthropods are ideal model organisms to study biomineralization because they regularly molt their exoskeletons and grow new ones in a relatively fast timescale, providing opportunities to track mineralization of entire tissues. Here, we monitored the biomineralization of the mantis shrimp dactyl club-a model bioapatite-based mineralized structure with exceptional mechanical properties-immediately after ecdysis until the formation of the fully functional club and unveil an unusual development mechanism.

Hierarchical Assembly of Tough Bioelastomeric Egg Capsules is Mediated by a Bundling Protein.

Marine snail egg capsules are shock-absorbing bioelastomers made from precursor "egg case proteins" (ECPs) that initially lack long-range order. During capsule formation, these proteins self-assemble into coiled-coil filaments that subsequently align into microscopic layers, a multiscale process which is crucial to the capsules' shock-absorbing properties. In this study, we show that the self-assembly of ECPs into their functional capsule material is mediated by a bundling protein that facilitates the aggregation of coiled-coil building blocks and their gelation into a prefinal capsule prior to final stabilization.

Integrative and comparative analysis of coiled-coil based marine snail egg cases - a model for biomimetic elastomers.

Integrative and comparative analyses of biomaterials systems offer the potential to reveal conserved elements that are essential for mechanical function. The approach also affords the opportunity to identify variation in designs at multiple length scales, enabling the delineation of a range of parameters for creating precisely tuned biomimetic materials. We investigated the molecular design and structural hierarchy of elastomeric egg capsules from the marine snail Pugilina cochlidium (family Melongenidae) and compared these data with all available published studies in order to infer the structure-property relationships of the egg case from the molecular to the macroscopic scale.