Unraveling Spiderman's glue silk

Abstract

Spiders spin high performance fibers that have diverse mechanical properties for movement, prey capture and protection of eggs. To investigate the mechanism by which spiders anchor their fibers to solid matrices, we solubilized the attachment discs from black widow spiders (cob weavers) and performed in‐solution tryptic digests followed by MS/MS analysis to identify novel peptides derived from glue silks. Combining matrix‐assisted laser desorption ionization tandem time‐of‐flight mass spectrometry and cDNA library screening, we have identified the first spider glue fibroin of the silk gene family called Pyriform Spidroin 1 (PySp1), as well as a closely related fibroin in orb weavers using conventional nucleic acid‐nucleic acid hybridization. Biophysical characterization of black widow spider attachment disc fibers using atomic force microscopy, as well as biochemical analyses of PySp1 using circular dichroism and NMR, demonstrate that PySp1 has distinct molecular features relative to other silk family members. Given the unique biophysical and chemical properties of PySp1, this fibroin could be ideal for use in spinning artificial silks through genetic engineering for different commercial applications, which include body armor, tissue engineering, sutures for the medical industry, and materials for the automobile and aerospace industry. This research was supported by the NSF RUI Grant MCB‐0544087.