Bromoacetate histidine residues

The presence of imidazole groups in the active site region of human carbonic anhydrase B has, in fact, been demonstrated by chemical modification. Thus, bromoacetate reacts specifically with the 3 -N of a histidine residue to give a partially active monocarboxymethyl enzyme (65). The reaction depends on the initial combination of the bromoacetate ion with the anion binding site (65,83). In a detailed study, Bradbury (83) has shown that the irreversible reaction at saturation with iodoacetate... 

Reactions of C enriched reactants with biologically interesting molecules have also been monitored by C NMR. Nigen et al. (184) carboxymethylat-ed harbor seal and sperm whale cyanoferrimyoglobin with enriched [2-i C] bromoacetate. Adducts of the NHg terminal residues of histidine and lysine were observed in the > C spectra. In denatured cyanoferrimyoglobins all histidine residues were converted to the dicarboxymethyl derivative. 

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