title: Effect of the conformation of concanavalin A on its affinity for manganous ion.
abstract: The stoichiometry of Mn2+ binding to concanavalin A at pH 6.4-7 which had been established in two independent studies [J.A. Sophianopoulos, A.J. Sophianopoulos, and W.C. MacMahon (1983) Arch. Biochem. Biophys. 223, 350-359; D.J. Christie, G.R. Munske, and J.A. Magnuson (1979) Biochemistry 18, 4638-4644] was challenged [C.F. Brewer, R.D. Brown, III, and S.H. Koenig (1983) Biochemistry 22, 3691-3702] on grounds of possible experimental errors. Additional evidence is presented in this study in support of the previous finding that at pH 6.4 only one Mn2+ binds per concanavalin A monomer of Mr 25,550. Also, evidence is presented showing that the results of Sophianopoulos et al. could not have been due to contamination by Ca2+. A comparison is made of the results in the three studies cited above which indicates that the concanavalin A used by Brewer et al. had decreased affinity for Mn2+ and it contained an appreciable fraction of concanavalin A incompetent of binding saccharides.
mesh_terms: D001059:Apoproteins / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D055598:Chemical Phenomena; D002621:Chemistry; D002942:Circular Dichroism; D003208:Concanavalin A / Q000378:metabolism*; D003956:Dialysis; D006863:Hydrogen-Ion Concentration; D006923:Hymecromone / Q000031:analogs & derivatives / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008345:Manganese / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence
chemical_list: D001059:Apoproteins; C048717:apoconcanavalin A; D003208:Concanavalin A; C008512:methylumbelliferyl-alpha-D-mannopyranoside; D006923:Hymecromone; D008345:Manganese; D002118:Calcium