人血白蛋白免疫优势抗原表位的筛选及鉴定

目的：筛选人血白蛋白（HSA）免疫优势抗原表位，为建立一种高特异性HSA制品快速检测方法提供基础。方法采用生物信息学方法比较人与其他物种（猪、马、牛、羊）白蛋白基因序列并预测其抗原表位，获得HSA免疫优势抗原表位；利用大肠杆菌优势密码子获得相应基因，插入PGEX-4T-2载体克隆表达得到重组HSA表位抗原；间接ELISA评价上述重组表位的特异性。结果筛选3个HSA抗原表位，分别位于H1〔126～162氨基酸（aa）〕、H2（314～355aa）、H3（373～424aa），获得相应基因片段；得到重组抗原的相对分子质量（Mr）分别为3.01×104、3.06×104和3.17×104；抗原活性检测显示373~424aa序列表位具有较高活性，其酶标抗体竞争抑制反应的IC50为1.635 mg/L，高于酶标HSA抗体。结论实验获得了特异性HSA免疫优势抗原表位，对研制一种快速、特异的HSA检测试剂具有重大意义。

Screening and identification of immunodominant epitope of human serum albumin

Objective To select the immunodominant epitope of human serum albumin(HSA)and provide the basis for set?ting up a special and rapid detecting method of HSA. Methods Bioinformatic method was used to compare protein sequences of hu?man,pig,horse,ox,and ovine,and the immunodominant epitopes of HSA were predicted. The E.coli preferred codons were used to design the DNA sequences of the selected epitopes. The genes of the epitopes were expressed after they were inserted into the PGEX-4T-2 vector. The recombinant antigens were identified and valued by HSA antibody with indirect ELISA. Results The length of the selected epitopes was H1〔126-162 amino acid(aa)〕,H2(314-355aa),and H3(373-424aa)and the relative molecular weight was 3.01×104,3.06×104 and 3.17×104,respectively. The epitope of 373-424 aa were more active and its cross-reactivity IC50 of enzyme-labeled antibody was 1.635 mg/L,which was higher than HSA(P<0.05). Conlusion The immunodominant epitope of HSA is obtained, which is significant for developing a rapid and special reagent of HSA.