Many biopolymers are stiff and brittle and require plasticizers. To optimize the choice and amount of plasticizer, the mechanisms behind plasticization need to be understood. For polar biopolymers, such as polysaccharides and proteins, plasticization depends to a large extent on the hydrogen bond network. In this study, glycerol-plasticized protein systems based on wheat gluten were investigated, in combination with the effects of water. The methodology was based on a combination of mechanical tests and molecular dynamics simulations (MD). The simulations accurately predicted the glycerol content where the experimental depression in glass transition temperature (T_g) occurred (between 20 and 30 wt% plasticizer). They also predicted the strong water-induced depression in T_g. Detailed analysis revealed that in the dry system, the main effect of glycerol was to break protein-protein hydrogen bonds. In the moist system, glycerol was partly outcompeted by water in forming hydrogen bonds with the protein, making the glycerol plasticizer less effective than in dry conditions. These results show that MD can successfully predict the plasticizer concentration at which the onset of efficient plasticization occurs. MD can therefore be an important tool for understanding plasticizer mechanisms, even in a complex system, on a level of detail that is impossible with experiments.

许多生物聚合物又硬又脆，需要增塑剂。为了优化增塑剂的选择和用量，需要了解增塑背后的机制。对于极性生物聚合物，如多糖和蛋白质，增塑在很大程度上取决于氢键网络。在这项研究中，结合水的影响，研究了基于小麦面筋的甘油增塑蛋白系统。该方法基于机械测试和分子动力学模拟 (MD) 的组合。模拟准确地预测了发生玻璃化转变温度 ( T _g )实验性降低时的甘油含量（增塑剂在 20 至 30 重量％之间）。他们还预测了强烈的水引起的抑郁症牛逼_{g ^}. 详细分析表明，在干燥系统中，甘油的主要作用是破坏蛋白质-蛋白质氢键。在潮湿的系统中，甘油在与蛋白质形成氢键方面部分被水击败，使得甘油增塑剂不如干燥条件下有效。这些结果表明，MD 可以成功地预测发生有效增塑的增塑剂浓度。因此，MD 可以成为了解增塑剂机制的重要工具，即使在复杂的系统中，其细节水平也是实验无法实现的。