Unraveling how spiders store their silk

Abstract

Spider silk is stronger than steel by weight and as stretchy as rubber. Scientists want to understand how spiders spin their silk so they can make artificial versions of the gossamer threads for use in sports gear or bulletproof vests. In a key insight to the spinning process, researchers have found that spiders store silk proteins as complex, tiered nanostructures inside their silk glands (Proc. Natl. Acad. Sci. USA 2018, DOI: 10.1073/pnas.1810203115). The findings explain how the arachnids pack the proteins at a superhigh concentration. Each glossy silk fiber is a string of large protein molecules. In the spider’s glands, these proteins mix with water and salt to form a highly concentrated gel-like fluid. Fifteen years ago, researchers hypothesized that the proteins form spherical nanostructures. “But nobody knew if these things were real,” says Gregory P. Holland, a chemist at San Diego State University. To find out if the nanoparticles