Tewari Y B, Goldberg R N
Chemical Thermodynamics Division, National Institute of Standards and Technology, Gaithersburg, MD 20899.
Biophys Chem. 1991 Apr;40(1):59-67. doi: 10.1016/0301-4622(91)85029-p.
High-pressure liquid chromatography and microcalorimetry have been used to study the thermodynamics of the hydrolysis reactions of a series of disaccharides. The enzymes used to bring about the hydrolyses were: beta-galactosidase for lactulose and 3-o-beta-D-galactopyranosyl-D-arabinose; beta-glucosidase for alpha-D-melibiose; beta-amylase for D-trehalose; isomaltase for palatinose; and alpha-glucosidase for D-turanose. The buffer used was sodium acetate (0.02-0.10 M and pH 4.44-5.65). For the following processes at 298.15 K: lactulose(aq) + H2O(liq) = D-galactose(aq) + D-fructose(aq), K0 = 128 +/- 10 and delta H0 = 2.21 +/- 0.10 kJ mol-1; alpha-D-melibiose(aq) + H2O(liq) = D-galactose(aq) + D-glucose(aq), K0 = 123 +/- 42 and delta H0 = -0.88 +/- 0.50 kJ mol-1; palatinose(aq) + H2O(liq) = D-glucose(aq) + D-fructose(aq), delta H0 = -4.44 +/- 1.1 kJ mol-1; D-trehalose(aq) + H2O(liq) = 2 D-glucose(aq), K0 = 119 +/- 10 and delta H0 = 4.73 +/- 0.41 kJ mol-1; D-turanose(aq) + H2O(liq) = D-glucose(aq) + D-fructose(aq), delta H0 = -2.68 +/- 0.75 kJ mol-1; and 3-o-beta-D-galactopyranosyl-D-arabinose(aq) + H2O(liq) = D-galactose(aq) + D- arabinose(aq),0H0 = 107 +/- 10 and delta H0 = 2.97 +/- 0.10 kJ mol-1.(ABSTRACT TRUNCATED AT 250 WORDS)
高压液相色谱法和微量量热法已被用于研究一系列二糖水解反应的热力学。用于引发水解的酶有：用于乳果糖和3 - O - β - D - 吡喃半乳糖基 - D - 阿拉伯糖的β - 半乳糖苷酶；用于α - D - 蜜二糖的β - 葡萄糖苷酶；用于D - 海藻糖的β - 淀粉酶；用于帕拉金糖的异麦芽糖酶；以及用于D - 松二糖的α - 葡萄糖苷酶。所使用的缓冲液是醋酸钠（0.02 - 0.10 M，pH 4.44 - 5.65）。对于298.15 K下的以下过程：乳果糖（水溶液）+ H₂O（液体）= D - 半乳糖（水溶液）+ D - 果糖（水溶液），K₀ = 128 ± 10，ΔH₀ = 2.21 ± 0.10 kJ/mol⁻¹；α - D - 蜜二糖（水溶液）+ H₂O（液体）= D - 半乳糖（水溶液）+ D - 葡萄糖（水溶液），K₀ = 123 ± 42，ΔH₀ = -0.88 ± 0.50 kJ/mol⁻¹；帕拉金糖（水溶液）+ H₂O（液体）= D - 葡萄糖（水溶液）+ D - 果糖（水溶液），ΔH₀ = -4.44 ± 1.1 kJ/mol⁻¹；D - 海藻糖（水溶液）+ H₂O（液体）= 2D - 葡萄糖（水溶液），K₀ = 119 ± 10，ΔH₀ = 4.73 ± 0.41 kJ/mol⁻¹；D - 松二糖（水溶液）+ H₂O（液体）= D - 葡萄糖（水溶液）+ D - 果糖（水溶液），ΔH₀ = -2.68 ± 0.75 kJ/mol⁻¹；以及3 - O - β - D - 吡喃半乳糖基 - D - 阿拉伯糖（水溶液）+ H₂O（液体）= D - 半乳糖（水溶液）+ D - 阿拉伯糖（水溶液），ΔH₀ = 107 ± 10，ΔH₀ = 2.97 ± 0.10 kJ/mol⁻¹。（摘要截取自250字）
