Natural spider silk with extraordinary mechanical properties is typically spun from more than one type of spidroin, including major and minor components. Although the main components of various spider silks have been widely studied, less people know about the molecular role of the minor silk components in spidroin self-assembly and fiber formation. This seriously hinders the design and production of high-performance artificial spider silk.

Recently, a research team led by Prof. Zhi Lin from Tianjin University has made a significant contribution to the understanding of the molecular and structural mechanisms of minor component in eggcase silk spinning. This result has been published in PNAS (https://doi.org/10.1073/pnas.2100496118).

Spider eggcase silk consists of major component TuSp1 and minor component TuSp2. This research identified the critical role of the minor eggcase silk component in promoting spidroin chain alignment and revealed the structural mechanism underlying TuSp2-mediated self-assembly of tubuliform spidroins. Furthermore, artificial fiber spun from the complex between recombinant TuSp1 and TuSp2 minispidroins exhibits considerably higher strength than its native counterpart. The strategy that employs spidroin complex, rather than single species of silk protein, from the same spider silk gland may be applicable for spinning other types of artificial silk fibers with predictable or tunable physical properties. These findings create a new framework for rationally designing silk biomaterials based on distinct roles of silk components.

Fig.1. The structural basis and micelle model of the interaction between TuSp2-RP and TuSp1-RP

By the School of Life Sciences

Editor: Yang Fan