Will site-specific biotin labeling with the EasyXpress Site-Specific Biotin kit alter the structure and function of my protein?
FAQ ID -877

A single label (biotinylated lysine) can be inserted at any position within a protein's amino acid sequence (except the start methionine) using the EasyXpress Site-Specific Biotin Kit, allowing selection of a label position which does not intefere with protein structure and function. Stoichiometry for biotin label incorporation is one biotin molecule per protein molecule.