Critical role of minor eggcase silk component in promoting spidroin chain alignment and strong fiber formation

Abstract

Significance Our manuscript is focused on the structural and functional role of minor silk component TuSp2 in spider eggcase silk formation. We present the structure of TuSp2 core domain and reveal how this domain renders main component TuSp1 more favorable for molecular chain alignment, which is critical for strong fiber formation. We further designed a series of biomimetic minispidroin complexes and showed that the artificial silk fiber can surpass its native counterpart in strength significantly. This study represents a distinct advance in understanding the critical role of the minor component in silk formation. The strategy developed in this study also throws light on spinning other types of artificial silk fibers with predictable physical properties.