Dalal P, Sönnichsen F D
Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106-4970, USA.
J Chem Inf Comput Sci. 2000 Sep-Oct;40(5):1276-84. doi: 10.1021/ci000449b.
Antifreeze proteins (AFPs) are a group of structurally very diverse proteins with the unique capability of binding to the surface of seed ice crystals and inhibiting ice crystal growth. The AFPs bind with high affinity to specific planes of the ice crystal. Previously, this affinity of AFPs has been ascribed to the formation of multiple hydrogen bonds across the protein-ice interface, but more recently van der Waals interactions have been suggested to be the dominant energetic factors for the adsorption. To determine whether van der Waals interactions are also responsible for the binding specificities of AFPs, the protein-ice interaction of the helical AFP Type I from winter flounder (HPLC6) was studied using a Monte Carlo rigid body docking approach. HPLC6 binds in the [1102] direction of the [2021] plane, with the Thr-Ala-Asn surface comprising the protein's binding face. The binding of HPLC6 to this ice plane is highly preferred, but the protein is also found to bind favorably to the [1010] prism plane using a different protein surface comprised of Thr and Ala residues. The results show that van der Waals interactions, despite accounting for most of the intermolecular energy (>80%), are not sufficient to completely explain the AFP binding specificity.
抗冻蛋白（AFPs）是一类结构极为多样的蛋白质，具有与籽晶冰表面结合并抑制冰晶生长的独特能力。AFPs以高亲和力与冰晶的特定平面结合。此前，AFPs的这种亲和力被归因于在蛋白质 - 冰界面形成多个氢键，但最近有人提出范德华相互作用是吸附的主要能量因素。为了确定范德华相互作用是否也对抗冻蛋白的结合特异性起作用，使用蒙特卡罗刚体对接方法研究了来自冬比目鱼的螺旋型I类抗冻蛋白（HPLC6）与冰的相互作用。HPLC6在[2021]平面的[1102]方向上结合，其苏氨酸 - 丙氨酸 - 天冬酰胺表面构成蛋白质的结合面。HPLC6与该冰平面的结合是高度优先的，但也发现该蛋白质使用由苏氨酸和丙氨酸残基组成的不同蛋白质表面与[1010]棱柱平面有良好的结合。结果表明，尽管范德华相互作用占分子间能量的大部分（>80%），但不足以完全解释抗冻蛋白的结合特异性。
