Background Proteomics is the new system biological approach to the study of proteins and protein variation on a large scale as a result of biological processes which can identificate several proteins at a given time in a sample. Proteomic analysis has provided important insights into ischaemic heart disease, heart failure, and cardiovascular pathophysiology. Blood represents one of the most accessible sources for biomarkers and has broad clinical significance. Serum or plasma samples provide an excellent source of materials for proteomic analysis.

Objectives The aim of this study was to seek the special plasma molecule in the plasma protein map from the patient with acute coronary syndrome (ACS) using proteomics.

Methods Plasma from 60 patients, 20 with acute myocardial infarction (AMI) and 20 with unstable angina (UA), was investigated. The control group included 20 age-matched volunteers. 2-DE-DIGE/MALDI-TOF- MS analysis was performed during the procedure. The optimal abundant proteins in plasma were removed with the polyclonal antibody affinity column.

Results With 2DE-DIGE/MALDI-TOF-MS analysis, 14 different expression proteins were found in plasma of patients with ACS. (1) As compared with the control, serum amyloid A2, CP20 kDa protein, alpha-1 antitrypsin, haptoglobin beta and alpha-2chain, C6 precursor and C4, fibrinogen gammar chain and fibrin beta were up-regulated in plasma from UA and AMI patients. (2) Meanwhile, apolipoprotein A-I, A-IV and A-IV precursor, TF 11 and 7 kDa protein, transthyretin, gelsolin and gelsolin precursor isoform 1, myosin-11, HBB Truncated beta-globin were down-regulated in plasma from ACS patients. (3) Moreover, ELISA analysis showed that SAA was up-regulated and gelsolin was down-regulated in the plasma of UAP and AMI.

Conclusions Various proteins involving in acute phase protein, complement system, and cytoskeleton, apolipoprotein, energy metabolism were participated in the procession of ACS. The newly discovered different proteins, serum amyloid A2 and gelsolin might be the special molecules for ACS. But further investigation should be carrying out in the future.