ANALYSIS OF CEREBROSPINAL-FLUID FROM PATIENTS WITH PSYCHIATRIC AND NEUROLOGICAL DISORDERS BY 2-DIMENSIONAL ELECTROPHORESIS - IDENTIFICATION OF DISEASE-ASSOCIATED POLYPEPTIDES AS FIBRIN FRAGMENTS

Two-dimensional electrophoresis (2-DE) of cerebrospinal fluid (CSF) samples- from 347 patients with various psychiatric and neurological disorders-and subsequent silver staining revealed two additional polypeptides (M(r) 40 000) in 49 % of Ill schizophrenics, 46% of 43 schizoaffective patients, 36% of 41 patients with affective disorders, 43 % of 28 patients with multiple sclerosis, but not in 25 patients without neurological symptomatology, nor in 9 patients with Lues, and in only 2 of 25 patients with AIDS. The two polypeptides, as detected by 2-DE, eluted after size exclusion chromatography in fractions containing proteins with M(r) > 200 000. After 2-DE of CSF samples, enriched by gel chromatography, the polypeptides were immobilized by blotting onto glass-fiber membranes and subjected to N-terminal sequencing. Polypeptide A was identified as beta-chain remnant (beta-2), derived from plasmin cleavage of fibrin(ogen). After size exclusion chromatography, 2-DE, and Western blotting, polypeptide A and B, as well as several other spots, reacted with fibrinogen antibodies, suggesting that the polypeptides are subunits of a fibrin degradation complex.