论文标题
膜粘附中的碳水化合物 - 碳水化合物相互作用是模糊和通用的
Weak carbohydrate-carbohydrate interactions in membrane adhesion are fuzzy and generic
论文作者
论文摘要
碳水化合物（例如三糖基序列）是细胞表面的关键成分。尽管进行了激烈的研究，但尚未很好地理解化合细胞或膜的碳水化合物之间的相互作用。在本文中，我们研究了膜粘附中的碳水化合物 - 碳水化合物相互作用，以及在溶液中，具有广泛的原子分子动力学模拟，超过了先前研究的模拟时间。对于Lex，我们获得了可溶性碳水化合物的缔合常数，脂质锚定碳水化合物的粘附能以及膜粘附中碳水化合物复合物的最大持续力，这与实验结果一致。因此，我们的模拟似乎提供了溶液和膜粘附过程中Lex-Lex相互作用的现实，详细的图片。在这张照片中，Lex-Lex相互作用是模糊的，即Lex对以各种短寿命的结合构象相互作用。对于由两个乳糖单位组成的合成四糖LAC 2，我们观察到类似的模糊相互作用，并获得可溶性和脂质锚定变体的缔合常数，这些变体与Lex的相应关联常数可比。因此，模拟中量化的模糊，弱碳水化合物 - 碳水化合物相互作用似乎是小型中性碳水化合物（如Lex和Lac 2）的通用特征。
Carbohydrates such as the trisaccharide motif LeX are key constituents of cell surfaces. Despite intense research, the interactions between carbohydrates of apposing cells or membranes are not well understood. In this article, we investigate carbohydrate-carbohydrate interactions in membrane adhesion as well as in solution with extensive atomistic molecular dynamics simulations that exceed the simulation times of previous studies by orders of magnitude. For LeX, we obtain association constants of soluble carbohydrates, adhesion energies of lipid-anchored carbohydrates, and maximally sustained forces of carbohydrate complexes in membrane adhesion that are in good agreement with experimental results in the literature. Our simulations thus appear to provide a realistic, detailed picture of LeX-LeX interactions in solution and during membrane adhesion. In this picture, the LeX-LeX interactions are fuzzy, i.e. LeX pairs interact in a large variety of short-lived, bound conformations. For the synthetic tetrasaccharide Lac 2, which is composed of two lactose units, we observe similarly fuzzy interactions and obtain association constants of both soluble and lipid-anchored variants that are comparable to the corresponding association constants of LeX. The fuzzy, weak carbohydrate-carbohydrate interactions quantified in our simulations thus appear to be a generic feature of small, neutral carbohydrates such as LeX and Lac 2.
