RESUMO
Objective To analyze the constituent of the 32 kD protein band and its expression in schizophrenia se?rum. Methods Sixty schizophrenia patients and 58 health controls were recruited. The serum samples were collected and precipitated with 7%PEG. The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was used to ob?tain the abnormal 32 kD proteins band in patients. This protein band was cut and then analyzed using mass spectrometric technique. Results The 32 kD protein band was present in 38 schizophrenia patients but not in control and positive rate was 63.33%. The mass spectrometric analysis showed that 32 kD protein band contained 14 proteins ranging from 30 kD to 35 kD, including 6 high-frequency proteins (cDNA coded protein 1 and 2, Apolin protein A-1, Isoform 2 of ficolin-2, Complement factor H and clusterin) and 8 low-frequency proteins (IgG H chain, zinc-alphg-2-glycoprotein, fermitin,family apolin protein L-1, isoform 10 of collectin-1, purine nucleoside, anne xin and cDNA coded protein 3). Three cD?NA coded unknown proteins were highly similar to complement C4-B, β2-glycoprotein and erythrocyte band 7 integral membrane protein. Conclusion There is a unknown specific 32 kD protein that is consisted mainly of fourteen proteins in serum of schizophrenia.