前胃泌素释放肽ProGRP生物信息学分析及抗原决定簇预测

Bioinformatics analysis and epitope prediction of pro-gastrin-releasing peptide(ProGRP)

目的:分析预测前胃泌素释放肽(ProGRP)蛋白结构及其抗原决定簇,为抗ProGRP单克隆抗体的筛选及其相应的抗原结合位点的确定提供可靠依据。方法:从NCBI网站获取ProGRP不同亚型的氨基酸序列进行比对分析(Clustalw),运用不同生物信息学软件分析蛋白理化性质(Protparam),跨膜区(TMHMM),二级结构、亲水性、表面可及性、柔韧性和抗原指数(DNAstar Protean),三级结构(Swiss Model)以及抗原决定簇(BepiPred-2.0及ABCpred)。结果:ProGRP具有3个同型异构体,属于亲水性蛋白,半衰期为30 h,无跨膜区;ProGRP氨基酸序列中含丰富的二级结构,包括α螺旋、β折叠、β转角和无规则卷曲;ProGRP具有5个潜在的抗原决定簇。结论:该研究筛选的抗原决定簇具有较高的准确性,为鉴定ProGRP单克隆抗体结合位点以及小细胞肺癌(SCLC)的诊治奠定了良好的基础。

Objective:To analyze and predict the structure of pro-gastrin-releasing peptide(ProGRP)and its epitope,and provide a reliable basis for the screening of anti-ProGRP monoclonal antibodies and the determination of their corresponding antigen binding sites.Methods:Amino acid sequences of different subtypes of ProGRP were obtained from NCBI website for alignment analysis(Clustalw).The physicochemical properties were analyzed by Protparam,the transmembrane helix by TMHMM,the secondary structure,hydrophilicity,surface accessibility,flexibility regions and antigen index by DNAstar Protean,the tertiary structure by Swiss Model,the epitopes by BepiPred-2.0 and ABCpred.Results:ProGRP had three isoforms,which were hydrophilic proteins with a half-life of 30 hours and no transmembrane region.There were abundant secondary structures in the amino acid sequence of ProGRP,includingα-helix,β-fold,β-turn and random curl.ProGRP had 5 potential epitopes.Conclusion:The antigenic determinants screened in this study have high accuracy,which lays a good foundation for identifying the binding site of ProGRP monoclonal antibody and the diagnosis and treatment of small cell lung cancer(SCLC).