Stronger than Kevlar
Researchers from the McKelvey School of Engineering at Washington University in St. Louis have developed a method that allows bacterial synthesis of the high-molecular muscle protein titin – one of the three main components of muscle tissue, which can then be twisted into heavy-duty fibers.
This production will be inexpensive, scalable and does not need the use of animals.
The characteristic mechanical properties are due to the large size of titin – it is the largest known protein.
Researchers have repeatedly tried to develop materials with similar properties to muscles for use in various fields, for example, in soft robotics. But for this we had to use live animal tissues. Fuzhong Zhang's group set a goal to make synthetic muscles with the help of E. coli bacteria, in whose DNA the gene encoding titin in rabbits was embedded.
The research team designed bacteria capable of synthesizing polymers with an ultra–high molecular weight and a size of about three megadaltons from smaller protein fragments - about 50 times the size of an average bacterial protein. Then, using a wet molding process, the scientists transformed the proteins into fibers with a diameter of about 10 microns.
The team analyzed the structure of the resulting fiber to determine the molecular mechanisms that underlie the unique combination of exceptional strength, rigidity and damping ability.
In addition to sewing special equipment (titanium fibers are stronger than Kevlar, the material used in the creation of bulletproof vests), titanium material also has the potential for use in various biomedical fields. Since it is almost identical to the proteins contained in muscle tissue, the new synthetic material is presumably biocompatible and therefore can be included in suture material, artificial organs and implants.
Zhang's research group does not intend to stop at synthetic muscle fibers. In the future, there will probably be more unique materials that will be available thanks to the new microbial synthesis strategy.
The authors have applied for a patent for this method of protein polymerization inside artificially created bacteria
Article by C.H.Bowen et al. Microbial production of megadalton titin yields fibers with advantageous mechanical properties is published in the journal Nature Communications.
Amina Ibragimova, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of Washington University in St. Louis: Synthetic biology enables microbes to build synthetic muscle.