(573i) Phase Behavior of Protein-Engineered Hydrogel Fibers

Responsiveness to external stimuli leads to the classification of protein hydrogels as “smart” biomaterials. Two of the most common external stimuli that can trigger self-assembly and thus gelation are temperature and pH. These two conditions, in addition to other environmental conditions, are closely entwined in determining the overall structure and function of a protein. Being able to understand and predict how environmental conditions affect the self-assembly of proteins will aid in efforts to design proteins and protein-based materials for specific applications on a sequences-specific level. Herein, we present a hydrogel that is formed the coiled-coil protein, Q, which is an engineered variant of the coiled-coil domain of cartilage oligomeric matrix protein (COMPcc). Specifically, the phase behavior of Q is investigated at different pH levels, in order to determine the effects of surface charge on fiber assembly and gelation. Through transmission electron microscopy, scanning electron microscopy, and circular dichroism among other techniques, we see that increasing pH yields stronger fiber networks, which results in hydrogels with faster gelation times and increased mechanical properties.