Squid-Based Proteins Can Repair Your Clothes
Written by Audrey Bantug
Edited by Tanishq Vaidya
May 2, 2021
Edited by Tanishq Vaidya
May 2, 2021
What’s the first thing that comes to mind when you hear the word “protein”? You probably think of meat or possibly even enzymes. Proteins also play important roles as structural components in living things, such as in hair, skin, and nails. How can this one type of molecule have so many different functions? It’s all because proteins consist of a chain of amino acids, which interact with each other in various ways to form a unique overall structure. These different structures can then result in specific functions that have inspired novel applications in modern technology.
Researchers at Pennsylvania State University have been investigating the uses of a protein derived from squid ring teeth, called SRT for short (Pena-Francesch & Demirel, 2019). Interestingly, the SRT protein has both beta sheets and disordered domains. Beta sheets are a type of secondary structure involving hydrogen bonds, giving the protein mechanical strength. Disordered domains are simply random coils of protein that allow for flexibility. Due to these unique properties, SRT protein can serve as a component of textiles and other fiber-based materials (Pena-Francesch et al., 2018c). Just a thin coating or some interwoven strands can prevent abrasions and even self-heal the fabric. One day, you might never have to worry about accidentally ripping your favorite shirt!
Another interesting application of the SRT protein is in electronics. About 11% of the amino acids found in the protein are histidines, which have a charged side group (Pena-Francesch & Demirel, 2019). When combined with MXenes, another conductive material, SRT proteins exhibited higher levels of electrical conductivity and electromagnetic interference compared to conventional metals . Combined with their strength and flexibility, SRT proteins can pave the way for stronger and more energy efficient electronic devices.
Although these proteins have much potential, mass production is not yet feasible or sustainable. In the previously mentioned study, the researchers initially harvested SRT proteins from their original source, squids (Pena-Francesch et al. 2018a). However, the average squid yielded only about 100 milligrams worth of the protein, not nearly enough for their experiments. Later, the researchers genetically modified bacteria to produce the SRT protein, but are currently unable to scale up this method for commercial use. Scientists are also figuring out how to synthesize the protein entirely from scratch, though they are still a long way from accomplishing this goal. It will take some time, but someday we’ll get to enjoy all the amazing properties of squid ring teeth proteins.
References
Pena-Francesch, A., Domeradzka, N. E., Jung, H., Barbu, B., Vural, M., Kikuchi, Y., et al. (2018a). Research update: programmable tandem repeat proteins inspired by squid ring teeth. APL Mater. 6:10701. doi: 10.1063/1.4985755
Pena-Francesch, A., Jung, H., Segad, M., Colby, R. H., Allen, B. D., and Demirel, M. C. (2018c). Mechanical properties of tandem-repeat proteins are governed by network defects. ACS Biomater. Sci. Eng. 4, 884–891. doi: 10.1021/acsbiomaterials.7b00830
Pena-Francesch, A., & Demirel, M. (2019). Squid-inspired tandem repeat proteins: functional fibers and films. Frontiers in Chemistry, 7(69). https://doi.org/10.3389/fchem.2019.00069
Image Source: “Loligo vulgaris with captured Spaurus aurata” by Miguel Cabanellas (Mediterranean Institute for Advanced Studies) licensed under CC BY 2.0.