The amine-donor substrate specificity of tissue-type transglutaminase. Influence of amino acid residues flanking the amine-donor lysine residue.

摘要: The amine-donor substrate specificity of tissue-type transglutaminase has been studied in a series recombinant αA-crystallin mutants. These mutant proteins have provided with potential lysine residue, flanked by different amino acid residues, the C-terminal extended arm αA-crystallin. A biotinylated amine-acceptor hexapeptide was used as probe for labelling sites. Wild-type bovine does not function an transglutaminase. Yet, upon introduction residue at or penultimate position, all αA-crystallins act substrates, although to extents. This shows that accessibility is primary requirement and enzyme broad tolerance towards neighbouring residues. However, nature flanking residues clearly affect reactivity residue. Notably, we found proline glycine front strong adverse effect on compared preceding leucine, serine, alanine arginine