Modification of Lysyl Side Chains Using Citraconic Anhydride: Figure 1.

INTRODUCTIONReversible masking of ε-amino groups of lysine is a valuable procedure for limiting trypsin hydrolysis of proteins to arginine peptide bonds. Citraconic anhydride is a reversible blocking agent of lysyl side chains. A major advantage of citraconylation is the ease with which the blocking group can be removed under conditions that will not lead to protein denaturation.