Here is a response from Jon Rice regarding the PNAS article the other day submitted by the Chinese scientists:
Hi Red,
Thanks for forwarding the article. I think that you may find the following response to be of interest.
Hey Ben,
If you read the study, they reported 35% level of MaSp1, in the silk protein construction, as a function of weighing different cocoons and inferring that the difference is the intended protein. This is not the same approach Kraig labs uses to determine silk composition. I did not see in the paper were their weight based assumption was verified through actual protein expression testing. MaSp1 is believed to increase the elasticity and not strength. This understanding was translated in their data, where the new silk underperformed wild type silk in strength, but was more elastic. As to the increase in elasticity, we are already seeing elasticity reaching and surpassing the levels in their reported testing. If I was able to cherry pick my best fiber sample ever I would show you strengths in excess of Kevlar and elasticity 50% higher than this study.
Our goal is materials performance, not percentage of protein. This study reinforces that the path we’re taking, here at Kraig; using the latest in gene edit techniques to improve silk performance will continue to deliver improved materials, regardless of the specific percent concentrations of any one particular protein.
Jon Rice
Chief Operations Officer
Best regards,
Ben Hansel
720.288.8495
Git 'er done and let 'er run! Git 'em while they're cheap!
Red
