Meeting Abstract

S4-12  Saturday, Jan. 5 15:00 - 15:30  Fibers on the Fly: Multiscale Mechanisms of Fiber Formation in the Capture Slime of Onychophorans BAER, A; SCHMIDT, S; MAYER, G; HARRINGTON, MJ*; University of Kassel, Germany; Heinrich-Heine-Universität, Düsseldorf, Germany; University of Kassel, Germany; McGill University, Montreal, Canada matt.harrington@mcgill.ca https://www.mcgill.ca/harringtonlab/

Many organisms evolved a capacity to form biopolymeric fibers outside their bodies for adaptive functions such as defense, prey capture, attachment and protection. In particular, the adhesive capture slime of velvet worms (Onychophora) is remarkable for its ability to rapidly form stiff fibers through mechanical drawing. Notably, fibers formed ex vivo from extracted slime can be dissolved in water and new fibers can be drawn from the solution, indicating that fiber formation is encoded in the biomolecules that comprise the slime. This talk presents recent findings on the biochemical and physicochemical principles guiding this process. Employing a multiscale cross-disciplinary approach utilizing techniques from biology, biochemistry, physical chemistry and materials science, we determined that the slime is a concentrated emulsion of nanoglobules comprised of proteins and lipids, stabilized via electrostatic interactions. Upon mechanical agitation, globules break apart, leading to spontaneous self-assembly and fibrillation of proteins – a completely reversible process. Recent investigations highlight the importance of subtle transitions in protein structure and charge balance. Our findings have clear relevance for understanding the evolutionary success of this adaptive prey capture behavior and for providing inspiration towards sustainable polymer processing.