Graduate School of Science, Kyushu University, Fukuoka 819-0395, Japan.
Faculty of Science, Kyusyu University, Fukuoka 819-0395, Japan.
J Phys Chem B. 2024 Jan 25;128(3):676-683. doi: 10.1021/acs.jpcb.3c06317. Epub 2024 Jan 10.
Addition of sugars such as sucrose to aqueous protein solutions generally stabilizes proteins against thermal denaturation by preferential exclusion of sugars from proteins (preferential hydration of proteins). In this study, we investigated the effect of sucralose, a chlorinated sucrose derivative, on protein stability and preferential solvation. Circular dichroism and small-angle X-ray scattering measurements showed that sucrose increased the denaturation temperature of myoglobin and was preferentially excluded from the protein, whereas sucralose decreased the denaturation temperature of myoglobin and was preferentially adsorbed to the protein. No clear evidence was obtained for the indirect effects of sucralose on protein destabilization via the structure and properties of solvent water from the physicochemical properties (mass density, sound velocity, viscosity, and osmolality) of aqueous sucralose solutions; therefore, we concluded that a direct protein-sucralose interaction induced protein destabilization.
在蛋白质水溶液中添加糖（如蔗糖）通常可通过糖对蛋白质的优先排斥（蛋白质的优先水合作用）来稳定蛋白质，防止其热变性。在这项研究中，我们研究了三氯蔗糖（蔗糖的氯化衍生物）对蛋白质稳定性和优先溶解的影响。圆二色性和小角 X 射线散射测量表明，蔗糖增加了肌红蛋白的变性温度，并优先从蛋白质中排斥，而三氯蔗糖降低了肌红蛋白的变性温度，并优先吸附到蛋白质上。从水合三氯蔗糖溶液的物理化学性质（质量密度、声速、粘度和渗透压）来看，没有明显的证据表明三氯蔗糖通过溶剂水的结构和性质对蛋白质的不稳定性产生间接影响；因此，我们得出结论，直接的蛋白质-三氯蔗糖相互作用导致了蛋白质的不稳定性。
