Protective action of trehalose and glucose on protein hydration shell clarified by using X-ray and neutron scattering
Protective action of trehalose and glucose on protein hydration shell clarified by using X-ray and neutron scattering
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DOI：
10.1016/j.physb.2018.03.040
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发表时间：
2018-12-15
影响因子：
2.8
通讯作者：
Ohta, Noboru
中科院分区：
文献类型：
--
作者：
Ajito, Satoshi;Hirai, Mitsuhiro;Ohta, Noboru
众所周知，糖可以保留蛋白质结构并保护变性。糖对蛋白质结构的保护作用已经在优先水合和/或糖与蛋白质之间的相互作用的问题下进行了讨论。利用同步辐射广角X射线散射（SR-WAXS）和小角中子散射（SANS）方法，我们成功地获得了海藻糖和葡萄糖对蛋白质结构和水合作用影响的直接证据。马骨骼肌肌红蛋白是一种典型的球状蛋白。使用的糖是海藻糖和葡萄糖，其浓度从0%w/w变化到35%w/w。结合理论散射函数模拟和拟合的实验SR-WAXS和SANS数据清楚地表明，这两种糖被优先排除在水化壳区的蛋白质，以保持水化壳密度。直至糖浓度接近25%w/w。与葡萄糖（单糖）相比，海藻糖（二糖）的蛋白质水化壳的保存作用更为明显，这可能与生物体在极端环境胁迫下优先产生海藻糖的作用有关。
Sugars are well known to retain protein structures and to protect denaturation. Protective actions of sugars on protein structures have been discussed under issues of preferential hydration and/or interaction between sugar and protein. By using synchrotron radiation wide-angle X-ray scattering (SR-WAXS) and small-angle neutron scattering (SANS) methods, we have succeeded to obtain a direct evidence of the effect of trehalose and glucose on a protein structure and hydration. Myoglobin from horse-skeletal muscles was used as one of typical globular proteins. The sugars used were trehalose and glucose whose concentrations were varied from 0% w/w to 35% w/w. The experimental SR-WAXS and SANS data combined with theoretical scattering function simulation and fitting clearly show that both sugars are preferentially excluded from the hydration-shell region of the protein to preserve hydration-shell density. up to the sugar concentration of similar to 25% w/w. Compared with that of glucose (monosaccharide), the preservation action of the protein hydration-shell is much evidently seen for the case of trehalose (disaccharide), which might relate to a role of the preferential production of trehalose by organisms against extreme environmental stress.