TY - JOUR
T1 - Interactions of asparagine-linked carbohydrates with concanavalin
T2 - A nuclear magnetic relaxation dispersion and circular dichroism studies
AU - Bhattacharyya, Lokesh
AU - Koenig, Seymour H.
AU - Brown, Rodney D.
AU - Fred Brewer, C.
PY - 1991
Y1 - 1991
N2 - By using near-UV circular dichroism (CD) and solvent proton nuclear magnetic relaxation dispersion measurements, three different conformational states have been detected in Ca2+-Mn2+-concanavalin A upon binding a variety of asparagine-linked carbohydrates. Two of these transitions have been described previously, one for the binding of monosaccharides such as methyl α-D-mannopyranoside and oligosaccharides with terminal α-Glc or α-Man residues, and the second for the binding of oligomannose and complex type carbohydrates (Brewer, C. F., and Bhattacharyya, L. (1986) J. Biol. Chem. 261, 7306-7310). The third transition occurs upon binding a bisected biantennary complex type carbohydrate with terminal GlcNAc residues. Temperature-dependent nuclear magnetic relaxation dispersion and CD measurements have identified regions of the protein near the two metal ion binding sites that are associated with the conformation changes, and Tyr-12, which is part of the monosaccharide binding site, as responsible for the CD changes. The results support our previous conclusions that the rotamer conformation of the (α 1, 6) arm of bisected complex type oligosaccharides binds to concanavalin A with dihedral angle ω = -60° whereas nonbisected complex type oligosaccharides bind with ω = 180° (Bhattacharyya, L., Haraldsson, M., and Brewer, C. F. (1987) J. Biol. Chem. 262, 1294-1299). The present findings also explain the effects of increasing chain length of bisected complex type carbohydrates on their interactions with the lectin.
AB - By using near-UV circular dichroism (CD) and solvent proton nuclear magnetic relaxation dispersion measurements, three different conformational states have been detected in Ca2+-Mn2+-concanavalin A upon binding a variety of asparagine-linked carbohydrates. Two of these transitions have been described previously, one for the binding of monosaccharides such as methyl α-D-mannopyranoside and oligosaccharides with terminal α-Glc or α-Man residues, and the second for the binding of oligomannose and complex type carbohydrates (Brewer, C. F., and Bhattacharyya, L. (1986) J. Biol. Chem. 261, 7306-7310). The third transition occurs upon binding a bisected biantennary complex type carbohydrate with terminal GlcNAc residues. Temperature-dependent nuclear magnetic relaxation dispersion and CD measurements have identified regions of the protein near the two metal ion binding sites that are associated with the conformation changes, and Tyr-12, which is part of the monosaccharide binding site, as responsible for the CD changes. The results support our previous conclusions that the rotamer conformation of the (α 1, 6) arm of bisected complex type oligosaccharides binds to concanavalin A with dihedral angle ω = -60° whereas nonbisected complex type oligosaccharides bind with ω = 180° (Bhattacharyya, L., Haraldsson, M., and Brewer, C. F. (1987) J. Biol. Chem. 262, 1294-1299). The present findings also explain the effects of increasing chain length of bisected complex type carbohydrates on their interactions with the lectin.
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M3 - Article
C2 - 2033071
AN - SCOPUS:0025819601
SN - 0021-9258
VL - 266
SP - 9835
EP - 9840
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 15
ER -