The multiple electrophoretic bands of mouse haemoglobins

Abstract

A survey of past work shows that certainty in the electrophoretic classification of mouse haemoglobins requires further understanding of the meaning of the multiple electrophoretic bands observed.Six electrophoretic bands are observed in all. Numbered in order of mobility they give the formulae 2 for Hb-s, 1235 for Hb-d, 1246 for Hb-p and 12345 for foetal haemoglobin (Hb-f). When mercaptoethanol is added to the electrophoretic medium these formulae become: 2 for Hb-s, 23 for Hb-d, 24 for Hb-p, 234 for Hb-f. Bands 5 and 6 and a fast ultra-centrifuge fraction both increase when samples are stored.Bands 5 of Hb-d, 6 of Hb-p, and probably 5 of Hb-f, are dimers of the whole haemoglobin molecule almost certainly joined by sulphur bridges. The monomers are bands 2 and 3 of Hb-d and 2 and 4 of Hb-p. Within each type interconversion of bands 2 and 3 and bands 2 and 4 has been observed.The hypothesis is suggested that Hb-d and Hb-p both exist as two conformational isomers. In each case one isomer is electrophoretically indistinguishable from Hb-s: the other permits the electrophoretic recognition of their differences in bands 3 and 4, and the formation of sulphur bridges to give bands 5 and 6.