The macromolecular properties of peanut agglutinin
Fish, W.W.; Hamlin, L.M.; Miller, R.L.
Archives of Biochemistry and Biophysics 190(2): 693-698
ISSN/ISBN: 0003-9861 PMID: 718172 Accession: 006712728
The dependence upon solution conditions of the quaternary structure and gross conformation of peanut [Arachis hypogaea] agglutinin was examined by sedimentation equilibrium, sedimentation velocity, gel chromatograpy and circular dichroism. At pH 8, the protein exists as a compactly folded tetramer of MW 98,000. Between pH 4.75 and pH 3.0, the molecular reversibly dissociates to a (still globular) dimer. In the presence of denaturants such as SDS [sodium dodecyl sulfate] or guanidinium chloride, the protein dissociates to its 4 equal-sized constituents polypeptide chains. The circular dichroic spectrum of peanut lectin exhibits changes in the near UV upon binding of lactose, whereas the far UV spectrum remains unchanged. Dissociation to the dimeric state produces subtle changes in both the near and far UV circular dichroic spectrum.