Immunological Studies on Glutamine Synthetase using Antisera Raised to the Two Plant Forms of the Enzyme fromPhaseolusRoot Nodules

Antisera specific for glutamine synthetase (GS) have been raised to the two forms of the enzyme from the plant fraction of root nodules of Phaseolus vulgaris. The two antisera recognized both forms of plant nodule GS and also the enzyme from some other higher plant tissues. However, the antiserum did not cross-react with GS from free-living or bacteroid Rhizobium Phaseolinor with the enzyme from representatives of green algae, fungi, mammals and bacteria. Results are presented which suggest that one of the forms of nodule GS is closely related to the root enzyme whereas the other, the 'nodule specific' form, has some antigenic differences