OBJECTIVES Understanding the novel coronavirus (COVID-19) mode of host cell recognition may help to fight the disease and save lives. The spike protein of coronaviruses is the main driving force for host cell recognition. METHODS In this study, the COVID-19 spike binding site to the cell-surface receptor (Glucose Regulated Protein 78 (GRP78)) is predicted using combined molecular modeling docking and structural bioinformatics. The COVID-19 spike protein is modeled using its counterpart, the SARS spike. RESULTS Sequence and structural alignments show that four regions, in addition to its cyclic nature have sequence and physicochemical similarities to the cyclic Pep42. Protein-protein docking was performed to test the four regions of the spike that fit tightly in the GRP78 Substrate Binding Domain β (SBDβ). The docking pose revealed the involvement of the SBDβ of GRP78 and the receptor-binding domain of the coronavirus spike protein in recognition of the host cell receptor. CONCLUSIONS We reveal that the binding is more favorable between regions III (C391-C525) and IV (C480-C488) of the spike protein model and GRP78. Region IV is the main driving force for GRP78 binding with the predicted binding affinity of -9.8 kcal/mol. These nine residues can be used to develop therapeutics specific against COVID-19.

中文翻译：

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COVID-19穗-宿主细胞受体GRP78结合位点预测。

目的了解宿主细胞识别的新型冠状病毒（COVID-19）模式可能有助于抗击该疾病并挽救生命。冠状病毒的刺突蛋白是宿主细胞识别的主要驱动力。方法在这项研究中，使用分子模型对接和结构生物信息学相结合的方法预测了COVID-19穗与细胞表面受体（葡萄糖调节蛋白78（GRP78））的结合位点。使用其对应的SARS峰值对COVID-19峰值蛋白质进行建模。结果序列和结构比对显示，除了其环状性质外，四个区域与环状Pep42具有序列和理化相似性。进行蛋白质-蛋白质对接以测试紧密结合在GRP78底物结合结构域β（SBDβ）中的刺突的四个区域。停靠的姿势表明，GRP78的SBDβ和冠状病毒刺突蛋白的受体结合域参与了对宿主细胞受体的识别。结论我们揭示了刺突蛋白模型和GRP78的区域III（C391-C525）和IV（C480-C488）之间的结合更有利。IV区是GRP78结合的主要驱动力，预计结合亲和力为-9.8 kcal / mol。这九个残基可用于开发针对COVID-19的治疗剂。IV区是GRP78结合的主要驱动力，预计结合亲和力为-9.8 kcal / mol。这九个残基可用于开发针对COVID-19的治疗剂。IV区是GRP78结合的主要驱动力，预计结合亲和力为-9.8 kcal / mol。这九个残基可用于开发针对COVID-19的治疗剂。