Meeting Abstract

S7.7  Tuesday, Jan. 6  Dynamic Mechanical Properties of Synthetic Resilin DUDEK, DM*; GOSLINE, JM; MICHAL, CA; DEPEW, TA; ELVIN, C; KIM, M; LYONS, R; DUMSDAY, G; Univ. of British Columbia; Univ. of British Columbia; Univ. of British Columbia; Univ. of British Columbia; CSIRO, Brisbane; CSIRO, Brisbane; CSIRO, Brisbane; CSIRO, Clayton dudek@zoology.ubc.ca

As a nearly ideal elastic protein, resilin simplifies the function, construction, and maintenance of structures that contain it (e.g. the cicada tymbal mechanism oscillating at 4 kHz), by allowing for a system without lubrication, friction, or abrasion of loaded parts with low heat production. It can be strained to more than three times its rest length, and suffers neither from creep or stress relaxation during long term static tests. Previously, we showed that >99% pure resilin from dragonflies acts on its rubber plateau below 200 Hz, and returns more than 95% of the energy input each cycle even at 1000 Hz. This is in stark contrast to the large energy dissipation seen at high frequency in the locust pre-alar arm, which is composed of only 76% resilin. Here we use dynamic mechanical analysis to show that synthetic resilin from both fruit flies and mosquitoes is highly elastic and able to return more than 90% of the energy input each cycle even at 100 Hz, making it one of the most resilient synthetic rubbers known. 13C NMR spectra show the amino acid backbone of the crosslinked protein to be highly mobile and confirm the absence of an ordered tertiary structure for this protein. The peptide sequences vary considerably between these two insect resilins, resulting in the mosquito sample being significantly less resilient and molecularly mobile than the fruit fly. The ability to study pure samples of isolated recombinant resilin from multiple species allows us to use the natural experiment of evolution to understand the effects of peptide sequence on the properties and structure of elastomeric proteins in general.