Tyrosine chemical modification reagents

Chemical modifications of proteins (enzymes) by reacting them with iV-acylimidazoles are a way of studying active sites. By this means the amino acid residues (e.g., tyrosine, lysine, histidine) essential for catalytic activity are established on the basis of acylation with the azolides and deacylation with other appropriate reagents (e.g., hydroxylamine). 

With the rapid advancement of microbore and reverse phase technology m HPLC, the escalating popularity of this analytical technique is not unexpected. Generally, in HPLC no cleanup procedure is necessary for biological samples. Some of the ammo acids can be analyzed directly without prior derivatization, as is the case with tyrosine, tryptophan, and their metabolites. However, the use of fluorogenic derivatization reagents is a common practice. The ammo group is the only one that requires chemical modification prior to analysis... 

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