The Effect of Iron Localization on Mussel Thread Strength

The marine mussel Mytilus californianus utilizes an extraorganismic tissue known as a byssal thread to attach to its environment in the wave-swept intertidal zone. These threads exhibit great strength, durability, and self-healing following deformation. Previous research suggests that these unique properties are due to the presence of protein-metal crosslinking between 3,4-dihydroxyphenylalanine (Dopa) side chains and Fe3+ ions that have been sequestered from the mussel’s aquatic environment. We propose that increasing the Fe3+ content in a thread will increase thread strength up to a certain point. We use a Bionix MTS tensile testing apparatus to subject threads to uniaxial tension, yielding mechanical values such as stress, strain, and modulus. Our tensile test data indicates that changing the iron concentrations in the threads’ surroundings has a noticeable effect on thread mechanical properties. Understanding the structure-function relationships of byssal threads can potentially impact the way synthetic materials are stabilized by metal ions.

Project Mentor: Yerpeng Tan

Faculty Advisor: Herbert Waite