Microbial production of megadalton titin yields fibers with advantageous mechanical properties

Manmade high-performance polymers are typically non-biodegradable and derived from petroleum feedstock through energy intensive processes involving toxic solvents and byproducts. While engineered microbes have been used for renewable production of many small molecules, direct microbial synthesis of high-performance polymeric materials remains a major challenge. Here we engineer microbial production of megadalton muscle titin polymers yielding high-performance fibers that not only recapture highly desirable properties of natural titin (i.e., high damping capacity and mechanical recovery) but also exhibit high strength, toughness, and damping energy - outperforming many synthetic and natural polymers. Structural analyses and molecular modeling suggest these properties derive from unique inter-chain crystallization of folded immunoglobulin-like domains that resists interchain slippage while permitting intra-chain unfolding. These fibers have potential applications in areas from biomedicine to textiles, and the developed approach, coupled with the structure-function insights, promises to accelerate further innovation in microbial production of high-performance materials.

Automated summary

The study engineered microbial production of high-performance fibers with properties similar to natural titin, but with higher strength, toughness, and damping energy than many synthetic and natural polymers. The unique inter-chain crystallization of folded immunoglobulin-like domains is suggested to be the key to these superior properties, allowing resistance to interchain slippage while permitting intra-chain unfolding. These fibers have potential applications in fields ranging from biomedicine to textiles, and the developed approach is expected to spur further innovation in microbial production of high-performance materials.