modular software wrapper architecture example

Spidroins are highly soluble in the gland and, when needed, efficiently self-assemble into insoluble fibres 4. Spider silk proteins, or spidroins, are large (250–500 kDa) and have a general architecture comprising a repetitive domain, accounting for at least 90% of the total protein sequence, flanked by non-repetitive N- and C-terminal domains.

Spiders can produce up to seven types of silk that surpass synthetic materials in ultimate tensile strength (i.e., maximum stress, or force per cross-sectional area, withstood before breaking) and toughness (i.e., energy absorbed before breaking) per unit weight 1, 2, 3. The structural transition of aciniform spidroin from a mostly α-helical dope to a mixed α-helix/β-sheet-containing fibre can be directly related to spidroin architecture and stability. AcSp1 structural stability varies locally, with the fifth helix denaturing most readily. Concatemers form fibres upon manual drawing with silk-like morphology and mechanical properties, alongside secondary structuring and orientation consistent with native AcSp1 fibres. Split-intein-mediated segmental NMR-active isotope-enrichment allowed unambiguous demonstration of modular and malleable “beads-on-a-string” concatemeric behaviour. Using solution-state NMR spectroscopy, we demonstrate that the 200 amino acid Argiope trifasciata AcSp1 repeat unit contrasts with previously characterized spidroins, adopting a globular 5-helix bundle flanked by intrinsically disordered N- and C-terminal tails. Aciniform (or wrapping) silk is the toughest spider silk and is devoid of the short amino acid sequence motifs characteristic of the other spidroins. Spiders store spidroins in their silk glands as high concentration aqueous solutions, spinning these dopes into fibres with outstanding mechanical properties.

Modular software wrapper architecture example