Blog @ NanoVic - Nanotechnology Blog

Despite its beautiful, floating appearance in the narrow walkways of your garden, spider silk is stronger than steel and can be extended 30-50% of its length before it breaks.  Unraveling the secrets behind the strength of spider silk is attracting a lot of research dollars - if we could replicate it synthetically, imagine the impact on fabric technology, tethering equipment and load-bearing materials.  As reported recently in Science Daily, the eternal question of how spider silk manages to be such an amazing natural substance is being tackled by researchers in Civil and Environmental Engineering at Massachusetts Institute of Technology, USA.  The group has recently published some interesting data.  Crazily enough, it apparently all boils down to the basic hydrogen bond.  Along the length of the spider silk, groups of 3-4 hydrogen bonds form nanocomposite structures within the protein assembly, binding together repeated stacks of short protein beta strands.  Overall, hydrogen bonds arranged in such groupings of 3-4 resist force and dissipate energy; any fewer bonds, and the silk is not strong enough. Any more, and there is no net gain in strength. This incredible arrangement of beta sheets and hydrogen bonds is also found in muscle tissue and amyloid fibres, suggesting that increasing protein strength by this method offered a distinct evolutionary advantage (evolution is my favourite topic at the moment). So next time you stumble through a web, and maniacally tear at your web-infested hair in utter panic, just spare a thought for the humble hydrogen bond and evolution. I know I will.