Sesbania rostrata root and stem nodule leghemoglobins: purification, and relationships among the seven major...

By anion-exchange chromatography, the nitrogen fixing photosynthetic stem nodules and nonphotosynthetic root nodules of Sesbania rostrata are shown to contain the same seven major components of leghemoglobin (Lb), numbered LbI-LbVII in order of elution, although in different proportions. No novel component was found in photosynthetic nodules. All components of Sesbania Lb are monomeric, with molecular weights varying between 15,000 and 17,000, and at least six of them are separate gene products. It is suspected that variable conjugation with nonprotein moieties might be partially responsible for the molecular weight differences and anomalous behavior observed between isoelectric focusing and anion-exchange chromatography.