Squid's Suckerin Proteins in Bits & Bytes

Abstract

The suckerins or the sucker ring teeth of the Jumbo Squid are block-copolymer-like structural proteins but without a mineral phase or covalent cross-linking. Interestingly, the amino acid composition of these set of proteins are quite similar to silk proteins, that feature exceptional mechanical properties like high tensile strength and great extensibility. The tooth structure is known to assemble into a nano-confined β-sheet polymer network, interspersed within less orderly amorphous mesh-work. Remarkably, this biomaterial exhibits mechanical properties that rival those of robust bioengineered polymers.In the current work we have combined experimental and computational investigations to identify suckerin protein structure inorder to bridge the structure-function-property relationship. Our atomic detailed calculations were used to elucidate the robust supramolecular network of simple building blocks that assemble via weak hydrogen bonds ultimately leading to superior mechanical properties in squid's sucker ring teeth. In silico approach was complemented with structure based biophysical experiments for enhanced understanding of its molecular/atomic design principle.Our work sets a platform for extensive molecular level investigations of the suckerin protein family. This may contribute towards understanding the source of mechanical strength and elasticity of the protein based suckerins. It will also provide an effective template for mimicking wide range of bio-inspired materials.