Crystalline Leghemoglobin. II.The Molecular Weights and Shapes of the two Main Components.

Abstract

The molecular weights of the two main components of leghemoglobin have been determined, on the basis of sedimentation and diffusion studies, to be 16,800 for the electrophor-etically faster component, and 15,400 for the slower one. The sedimentation constants, extrapolated to infinite dilution, were 2.01 S for the electrophoretically faster component, and 2.04 S for the slower one, whereas the diffusion constant was 11.18 F for the faster component and 12.35 F for the slower one. The partial specific volume of the unresolved material was 0.740 ml/g. The molar frictional ratio was 1.118 for the electrophoretically faster component and 1.043 for the slower one. The results of this study show that the two main components of leghemoglobin differ slightly from each other in molecular size and shape.