Multimedia Gallery - Visualization
Unraveling the Secrets of Spider Silk
The strength of a biological material such as spider silk lies in the specific geometric configuration of structural proteins, which have small clusters of weak hydrogen bonds that work together to resist force and dissipate energy. The Massachusetts Institute of Technology's Civil and Environmental Engineering (CEE) department, in collaboration with SDSC researcher Ross Walker, found that this structure is as strong as steel, even though the "glue" of hydrogen bonds that hold spider silk together at the molecular level is 100 to 1,000 times weaker than steel's metallic bonds or Kevlar's covalent bonds. MIT Professor Markus Buehler and graduate student Sinan Keten found that three or four bonds provide a maximum resistance level that exceeds that of many metals - but that more than four bonds led to much-reduced resistance.
This rendering, based on modeling and large-scale simulations by SDSC's IBM Blue Gene/L supercomputer, shows the structure of a beta-sheet protein, Z1-Z2 telethonin complex, in the giant muscle protein titin. The inset shows the orientation of the protein backbone of three beta strands (in gold) with hydrogen bonds (dashed lines) holding the assembly together.
Image courtesy of Ross Walker of SDSC, MIT and the Protein Data Bank
Source: San Diego Supercomputer Center, UC San Diego