Detection of labile sulfide in serum albumin

An artificial non-heme iron protein was synthesized from serum albumin in the presence of ferrous ammonium sulfate and mercaptoethanol.The absorption spectrum of the synthesized protein displays maxima at 279 mμ and 386 mμ with two broad peaks at 327 mμ and 630 my. By chemical analyses, the protein contains non-heme iron and labile sulfide in approximately equimolar amounts. It is concluded that labile sulfide originates from an iron-coordinared complex.