Expression Of CTnI Specific Antigen Sites And Antibodies Detection

Cardiac Troponin I (cTnI) is unique to heart. Because of it's high sensitivity and specificity, and lasting for a long time in the blood stream of patients, cTnI has been considered to be the golden biochemistry marker in diagnosis of myocardial injury, especially acute myocardial infarction. This work is committed to obtaining the diagnosed antibodies through immunizing BALB/C mice by recombinant antigen, which is consist of two specific epitope sites of human cardiac Troponin I.Two specific epitope sites of human cardiac Troponin I (hcTnI), 38aa-52aa and 87aa-97aa, which can stably exist in the blood serum of acute myocardial infarction (AMI) patients, were selected as objective gene sequences and isolated by 5 lysines with low immunogenicity. Two specific epitopes and lysines constituted AA gene sequence. Plasmid pMAL-Antigen consisting 5AAs after maltose binding protein (MBP) was constructed by two restriction endonucleases , BamHI and BgLII. The pMAL-Antigen plasmid was diverted into E. coli BL21 (DE3) , and MBP-Antigen fusion protein was induced by 1.0 mmolL^-1 IPTG in E. coli BL21 (DE3). The MBP-Antigen fusion protein was purified by Amylose- resin. The result showed that protein Antigen of MBP-Antigen fusion protein was partially reduced from C end. The purity of MBP-Antigen fusion protein was over 95%. The hyper-purified MBP-Antigen fusion protein was injected into BALB/C mice and antibodies were detected by ELISA. These antibodies could be applied in the diagnosis of AMI and myocardial damage.