目的:通过计算机辅助的氨基酸定点突变及分子对接研究血型A抗原模拟多肽(EYWYCGMNRTGC)中关键的氨基酸残基。方法:通过在线服务器PEP-FOLD构建丙氨酸突变后多肽的三维结构,通过软件Autodock Vina将多肽与血型A抗体(PDB:1jv5)进行对接,计算亲和力,通过分析亲和力的变化确定模拟多肽中的关键氨基酸残基。结果:肽EYWYCGMNRTGC与1jv5的对接最小自由能为-6.3kcal/mol,其中E1、W3、T10、C12经丙氨酸替换后与1jv5的亲和自由能分别增加为-6.1kcal/mol、-5.4kcal/mol、-6.0kcal/mol、-6.1kcal/mol。结论:血型A抗原模拟肽EYWYCGMNRTGC中的关键氨基酸可能是E1、W3、T10、C12。 OBJECTIVE: To study the key amino acid residues in the blood group A antigen mimetic polypeptide (EYWYCGMNRTGC) by computer-aided site-directed mutagenesis and molecular docking. Methods: The three-dimensional structure of alanine-mutated polypeptide was constructed by on-line server PEP-FOLD. The polypeptide was linked to the blood group A antibody (PDB: 1jv5) by the software Autodock Vina to calculate the affinity. The affinity of the polypeptide was determined by analyzing the change of affinity Key amino acid residues. Results: The minimum free energy of the docking of peptide EYWYCGMNRTGC with 1jv5 was -6.3 kcal / mol, and the affinity free energy of E1, W3, T10, C12 and 1jv5 after alanine substitution increased to -6.1 kcal / mol, -5.4 kcal / mol, -6.0 kcal / mol, -6.1 kcal / mol. Conclusion: The key amino acids in EYWYCGMNRTGC, a type A antigen peptide, may be E1, W3, T10 and C12.