When the SH groups of various derivatives of human haemoglobin are converted into their mercuric mercaptides small changes are observed in the optical rotatory dispersion in the range 385-294mmu. These changes are proportionately greater for the reactive than for the unreactive SH groups. These observations have been interpreted in terms of the conformational changes that are likely to occur in the haemoglobin molecule on modification of the SH groups.
