α-烯醇化酶的翻译后修饰对类风湿关节炎免疫诊断价值

The value of post-translational modification of α-enolase in the diagnosis of rheumatoid arthritis

探讨α-烯醇化酶(α-enolase,ENO1)在类风湿关节炎(rheumatoid arthritis, RA)中的诊断意义。经过原核表达、Ni柱纯化等操作,成功得到ENO1蛋白。将纯化的蛋白分别进行瓜氨酸化及氨甲酰化修饰,得到瓜氨酸化α-烯醇化酶(citrullinatedα-enolase peptide,cit-ENO1)、氨甲酰化α-烯醇化酶(carbamylatedα-enolase peptide, carp-ENO1)以及瓜氨酸化氨甲酰化α-烯醇化酶(citrullinated-carbamylatedα-enolase peptide, cit-carp-ENO1)。选取RA患者30例(RA组)以及同期体检正常者35例(对照组),采用ELISA探究未修饰的蛋白以及这3种修饰后的蛋白对RA患者的诊断价值。通过SPSS软件构建ROC曲线对不同修饰蛋白的诊断效能进行评估,当cut-off值取95%的特异度时,carp-ENO1的灵敏度为26.7%,cit-ENO1的灵敏度为46.7%,cit-carp-ENO1的灵敏度为63.3%。ENO1蛋白修饰之后对RA检出率显著提高,提示瓜氨酸化或者氨甲酰化之后的蛋白作为抗原对RA具有一定的诊断参考价值。

This study was undertaken to explore the diagnostic value ofα-enolase（ENO1）for rheumatoid arthritis patients.After prokaryotic expression and purification by Ni column,ENO1 protein was successfully obtained.Then the purified protein was citrullinated and carbamylated,and we got three peptides,citrullinatedα-enolase peptide（cit-ENO1）,carbamylatedα-enolase peptide（carp-ENO1）and citrullinated-carbamylatedα-enolase peptide（cit-carp-ENO1）.Finally,their sensitivity and specificity were measured by ELISA method with 30 RA patients and 35 healthy persons.The sensitivity and specificity of different modified proteins was analyzed by the ROC curve.When the cut-off of specificity was 95%,the sensitivity of carp-ENO1 was 26.7%,the cit-ENO1 was 46.7% and the cit-carp-ENO1 was 63.3 %.The detection rate of rheumatoid arthritis after the modification of ENO1 was significantly increased,suggesting that citrullinated or carbamylated proteins have important diagnostic value for rheumatoid arthritis.