41] Modification of histidyl residues in proteins by diethylpyrocarbonate

Abstract

Publisher Summary Diethylpyrocarbonate has been shown to react specifically or stoichiometrically with a single histidyl residue in certain proteins. In other cases, the modification of activity has been correlated with the modification of one or more histidyl residues despite the possible modification of other residues; this correlation is facilitated by the fact that hydroxylamine removes the carbethoxy group from modified histidyl residues and tyrosyl residues, but not that of modified lysyl or sulfhydryl residues. Several enzymes have been shown to be inactivated by the modification of a residue other than a histidyl residue. Thus, although diethylpyrocarbonate does not always react specifically with histidyl residues in proteins, it is more selective than other acylating agents and can give useful information about the role of histidyl residues in many proteins. This chapter describes the way optimal conditions for reaction should be determined and the way possible side reaction should be examined.