[56] Carbodiimide modification of proteins.

A carbodiimide-nucleophile procedure for modifying carboxyl groups in proteins can be utilized under mild conditions for the quantitative determination of all carboxyl groups or for the modification of selected residues in activity studies. The method allows numerous variations both in the activating carbodiimide and in the nature of the nucleophile. Side reactions do occur but can be corrected for.