Hypervariable region protein modification with

Weinstein et al. (133), and applied to protein 315 (314-136). Bromo-acetyl-V-Dnp-ethylenediamine (BADE) was found to be capable of affinity labeling at least 70% of the active sites of protein 315 with little modification of side chains outside the site. Ninety-six percent of the radioactive affinity label was found in the L chain, where it was localized to tyrosine 34—the same residue that was labeled with Metzger s dia-zonium reagent. The evidence is thus convincing that this tyrosine, located in a hypervariable region, is intimately associated with the Dnp-binding site. 

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