The solubility of hemoglobins A and S reconstituted with various metalloporphyrins

The solubilities of hemoglobins A and S, reconstituted with various metalloporphyrins, in concentrated phosphate solutions are reported. In HbA the metallo-substituted derivatives have solubilities identical to Fe(II)HbAO2, except for PorHbA, which is less soluble. In HbS the central metal influences the solubility in the order Fe(II)HbSO2 greater than Cu(II)HbS greater than Ni(II)HbS greater than Zn(II)HbS approximately of porphyrinHbS greater than Fe(II)HbS. The changes in solubility properties of metallo-substituted HbS is probably related to conformational changes which alter interactions among hemoglobin molecules.