Exploring enzymatic catalysis at a solid surface: a case study with transglutaminase-mediated protein immobilization.

The factors affecting enzymatic protein immobilization with microbial transglutaminase (MTG) were explored. As model proteins, enhanced green fluorescent protein (EGFP) and glutathione S-transferase (GST) were chosen and tagged with a neutral Gln-donor substrate peptide for MTG (Leu-Leu-Gln-Gly, LLQG-tag) at their C-terminus. To create a specific surface, displaying reactive Lys residues, to be cross-linked with the Gln residue in the LLQG-tag of target proteins by MTG catalysis, a polystyrene surface was physically coated with beta-casein.