Functional glass surface displaying a glutamyl donor substrate for transglutaminase‐mediated protein immobilization

AbstractA chemically modified glass surface displaying a glutamyl donor substrate peptide (Z‐QG) was developed for microbial transglutaminase (MTG)‐mediated immobilization of recombinant proteins tagged with an MTG‐reactive lysine‐containing substrate peptide (K‐tag). To evaluate the surface modification conditions affecting the enzymatic protein immobilization, we employed an amino‐modified 96‐well glass plate as a base and prepared three types of glass surfaces displaying Z‐QG. Validation of the Z‐QG modified glass surfaces with recombinant enhanced green fluorescent proteins revealed that the insertion of a di(ethylene glycol) linker between the terminal Z‐QG moiety and the base not only enhances enzymatic protein immobilization efficiency but also decreases nonselective protein adsorption. A bacterial alkaline phosphatase fused with a K‐tag at the N terminus was also successfully immobilized to the designed glass surface, suggesting that the chemically modified glass surface displaying a spatially controlled glutamyl donor substrate is a potential platform for MTG‐mediated fabrication of protein‐based solid biomaterials.