The dissociation and recombination of subunits of human, horse, and canine hemoglobin

Experiments on the hybridization of various forms of human hemoglobin and of hemoglobins of different species at acid and alkaline pH raise a number of questions. In this paper we report experiments on the attempted hybridization of human and canine, and human and horse, hemoglobins by two hitherto untried procedures. In one of these the two hemoglobins were kept together at neutral pH and high ionic strength (I = 3), where dissociation into half molecules may be assumed to occur, and then dialysed back to an ionic strength of 0·1. In the other a mixture of the globins of the two species, under conditions where these are dissociated either into half or quarter molecules, was combined with heme to obtain the reconstituted hemoglobins. In both cases the results were negative, i.e. no hybrid forms were produced.