Protein and amino acid composition of silks from the cob weaver, Latrodectus hesperus (black widow)

The silks from the cob weaving spider, Latrodectus hesperus (black widow), have been examined with the goal of expanding our understanding of the rela tionship between the protein structure and mechanical performance of these unique biomaterials. The scaffolding, dragline and inner egg case silks eac h appear to be distinct fibers based on mole percent amino acid composition and polypeptide composition. Further, we find that the amino acid composit ion of dragline and egg case silk are similar to the analogous silks produc ed by orb weaving spiders, while scaffolding silk may represent a novel sil k. The black widow silks are comprised of multiple high molecular weight po lypeptides, however, the egg case and scaffolding silks also contain some s maller polypeptides. (C) 1999 Elsevier Science B.V. All rights reserved.