TY - JOUR
T1 - Thermodynamics of carbohydrate binding to galectin-1 from Chinese hamster ovary cells and two mutants. A comparison with four galactose- specific plant lectins
AU - Gupta, Dipti
AU - Cho, Moonjae
AU - Cummings, Richard D.
AU - Brewer, C. Fred
PY - 1996
Y1 - 1996
N2 - The thermodynamics of carbohydrate binding to the 14 kDa dimeric β- galactoside-binding lectin galectin-1 (Gal-1) from Chinese hamster ovary cells and four galactose-specific plant lectins were investigated by isothermal titration microcalorimetry. Recombinant Gal-1 from Escherichia coli, a Cys→Ser mutant with enhanced stability (C2S-Gal-1), and a monomeric mutant of the lectin (N-Gal-1) were studied along with the soybean agglutinin and the lectins from Erythrina indica, Erythrina crystagalli, and Erythrina corollodendrum. Although the pattern of association constants of the Erythrina lectins was similar for mono- and disaccharides, variations exist in their enthalpy of binding (-ΔH) values for individual carbohydrates. While the Erythrina lectins show greater affinities and -ΔH values for lactose and N-acetyllactosamine, the soybean agglutinin possesses similar affinities for methyl β-galactopyranoside, lactose, and N-acetyllactosamine and a greater -ΔH value for the monosaccharide. Gal-1 and the plant lectins possess essentially the same affinities for N-acetyllactosamine; however, the animal lectin shows a lower -ΔH value and more favorable binding entropy for the disaccharide. While Gal-1, C2S-Gal-1, and N-Gal-1 all possess essentially the same affinities for N-acetyllactosamine, the two mutants possess much lower -ΔH values, even though the mutation site(s) are far removed from the carbohydrate binding site. These results indicate that there are different energetic mechanisms of carbohydrate binding between galectin-1, its two mutants, and the Gal-specific plant lectins.
AB - The thermodynamics of carbohydrate binding to the 14 kDa dimeric β- galactoside-binding lectin galectin-1 (Gal-1) from Chinese hamster ovary cells and four galactose-specific plant lectins were investigated by isothermal titration microcalorimetry. Recombinant Gal-1 from Escherichia coli, a Cys→Ser mutant with enhanced stability (C2S-Gal-1), and a monomeric mutant of the lectin (N-Gal-1) were studied along with the soybean agglutinin and the lectins from Erythrina indica, Erythrina crystagalli, and Erythrina corollodendrum. Although the pattern of association constants of the Erythrina lectins was similar for mono- and disaccharides, variations exist in their enthalpy of binding (-ΔH) values for individual carbohydrates. While the Erythrina lectins show greater affinities and -ΔH values for lactose and N-acetyllactosamine, the soybean agglutinin possesses similar affinities for methyl β-galactopyranoside, lactose, and N-acetyllactosamine and a greater -ΔH value for the monosaccharide. Gal-1 and the plant lectins possess essentially the same affinities for N-acetyllactosamine; however, the animal lectin shows a lower -ΔH value and more favorable binding entropy for the disaccharide. While Gal-1, C2S-Gal-1, and N-Gal-1 all possess essentially the same affinities for N-acetyllactosamine, the two mutants possess much lower -ΔH values, even though the mutation site(s) are far removed from the carbohydrate binding site. These results indicate that there are different energetic mechanisms of carbohydrate binding between galectin-1, its two mutants, and the Gal-specific plant lectins.
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U2 - 10.1021/bi961458+
DO - 10.1021/bi961458+
M3 - Article
C2 - 8952472
AN - SCOPUS:0029908797
SN - 0006-2960
VL - 35
SP - 15236
EP - 15243
JO - Biochemistry
JF - Biochemistry
IS - 48
ER -