Elasticity tuning of a hexameric hemoprotein-based hydrogel by mutation of its protein building block

Abstract

Abstract Mutants of a hexameric hemoprotein reconstituted with an acryloyl group-tethered heme were prepared and used as cross-linkers to produce polyacrylamide hydrogels to evaluate the effect of mutations on their elastic modulus. The mutations decrease the heme-binding affinities in a solution state, reducing the Young's modulus by 30% relative to that of the wild-type protein-based hydrogel. Furthermore, a stimuli-responsive gel–sol transition occurs upon reduction of the mutant-based gel. This work indicates that the molecular-level heme affinity for the cross-linked protein units has an important influence on macro-level mechanical properties.