Goldberg R N, Bell D, Tewari Y B, McLaughlin M A
Chemical Thermodynamics Division, National Institute of Standards and Technology, Gaithersburg, MD 20899.
Biophys Chem. 1991 Apr;40(1):69-76. doi: 10.1016/0301-4622(91)85030-t.
Microcalorimetry has been used to determine enthalpy changes for the hydrolysis of a series of oligosaccharides. High-pressure liquid chromatography was used to determine the extents of reaction and to check for any possible side reactions. The enzyme glucan 1,4-alpha-glucosidase was used to bring about the following hydrolysis reactions: (A) maltose(aq) + H2O(liq) = 2D-glucose(aq); (B) maltotriose(aq) + 2H2O(liq) = 3D-glucose(aq); (C) maltotetraose(aq) + 3H2O(liq) = 4D-glucose(aq); (D) maltopentaose(aq) + 4H2O(liq) = 5D-glucose(aq); (E) maltohexaose(aq) + 5H2O(liq) = 6D-glucose(aq); (F) maltoheptaose(aq) + 6H2O(liq) = 7D-glucose(aq); (G) amylose(aq) + nH2O(liq) = (n + 1) D-glucose(aq); and (H) panose(aq) + 2H2O(liq) = 3D-glucose(aq); (J) isomaltotriose(aq) + 2H2O(liq) = 3D-glucose(aq). The enzyme beta-fructofuranosidase was used for the reactions: (K) raffinose(aq) + H2O(liq) = alpha-D-melibiose(aq) + D-fructose(aq); and (L) stachyose(aq) + H2O(liq) = o-alpha-D-galactopyranosyl-(1----6)- alpha-o-D-galactopyranosyl-(1----6)-alpha-D-glucopyranose + D-fructose(aq). The results of the calorimetric measurements (298.15 K, 0.1 M sodium acetate buffer, pH 4.44-6.00) are: delta H0A = -4.55 +/- 0.10, delta H0B = -9.03 +/- 0.10, delta H0C = -13.79 +/- 0.15, delta H0D = -18.12 +/- 0.10, delta H0E = -22.40 +/- 0.15, delta H0F = -26.81 +/- 0.20, delta H0H = 1.46 +/- 0.40, delta H0J = 11.4 +/- 2.0, delta H0K = -15.25 +/- 0.20, and delta H0L = -14.93 +/- 0.20 kJ mol-1. The enthalpies of hydrolysis of two different samples of amylose were 1062 +/- 20 and 2719 +/- 100 kJ mol-1, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
微量量热法已被用于测定一系列寡糖水解的焓变。采用高压液相色谱法测定反应程度并检查是否存在任何可能的副反应。使用葡聚糖1,4-α-葡糖苷酶引发以下水解反应：(A) 麦芽糖（水溶液）+ H₂O（液体）= 2D-葡萄糖（水溶液）；(B) 麦芽三糖（水溶液）+ 2H₂O（液体）= 3D-葡萄糖（水溶液）；(C) 麦芽四糖（水溶液）+ 3H₂O（液体）= 4D-葡萄糖（水溶液）；(D) 麦芽五糖（水溶液）+ 4H₂O（液体）= 5D-葡萄糖（水溶液）；(E) 麦芽六糖（水溶液）+ 5H₂O（液体）= 6D-葡萄糖（水溶液）；(F) 麦芽七糖（水溶液）+ 6H₂O（液体）= 7D-葡萄糖（水溶液）；(G) 直链淀粉（水溶液）+ nH₂O（液体）= (n + 1) D-葡萄糖（水溶液）；以及(H) 潘糖（水溶液）+ 2H₂O（液体）= 3D-葡萄糖（水溶液）；(J) 异麦芽三糖（水溶液）+ 2H₂O（液体）= 3D-葡萄糖（水溶液）。使用β-呋喃果糖苷酶进行反应：(K) 棉子糖（水溶液）+ H₂O（液体）= α-D-蜜二糖（水溶液）+ D-果糖（水溶液）；以及(L) 水苏糖（水溶液）+ H₂O（液体）= o-α-D-吡喃半乳糖基-(1→6)-α-D-吡喃半乳糖基-(1→6)-α-D-吡喃葡萄糖 + D-果糖（水溶液）。量热测量结果（298.15 K，0.1 M醋酸钠缓冲液，pH 4.44 - 6.00）为：ΔH₀A = -4.55 ± 0.10，ΔH₀B = -9.03 ± 0.10，ΔH₀C = -13.79 ± 0.15，ΔH₀D = -18.12 ± 0.10，ΔH₀E = -22.40 ± 0.15，ΔH₀F = -26.81 ± 0.20，ΔH₀H = 1.46 ± 0.40，ΔH₀J = 11.4 ± 2.0，ΔH₀K = -15.25 ± 0.20，以及ΔH₀L = -14.93 ± 0.20 kJ mol⁻¹。两种不同直链淀粉样品的水解焓分别为1062 ± 20和2719 ± 100 kJ mol⁻¹。（摘要截断于250字）
