title: Search for peptidic "middle molecules" in uremic sera: isolation and chemical identification of fibrinogen fragments.
abstract: According to the "middle molecule" (MM) hypothesis, the uremic solutes ranging from 500 to 5,000 Da are insufficiently eliminated by conventional hemodialysis and may act as uremic toxins. However, because of the methodological difficulties of MM purification, their chemical analysis is complicated and the precise structure of these molecules remains obscure. In the present study, a new micro-preparative procedure including SDS electrophoresis and liquid chromatography was applied for isolation of MM peptides from uremic sera. Microsequencing and MS/MS analyses of these peptides showed that most of the identified MM (22 out of 23) represented the N- and C-terminal fragments of the alpha- and beta-chains of fibrinogen. The obtained data provide new information on the precise structure of fibrinogen fragments accumulating in uremic serum as MM.
authors.affiliation: Heller Institute of Medical Research, Sheba Medical Center, Tel Aviv University, Tel-Hashomer 52621, Israel. kaplanb@sheba.health.gov.il
authors.forename: Batia
authors.initials: B
authors.lastname: Kaplan
authors.forename: Miriam
authors.initials: M
authors.lastname: Cojocaru
authors.forename: Edward
authors.initials: E
authors.lastname: Unsworth
authors.forename: Aaron
authors.initials: A
authors.lastname: Knecht
authors.forename: Brian M
authors.initials: BM
authors.lastname: Martin
mesh_terms: D016022:Case-Control Studies; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D005340:Fibrinogen / Q000737:chemistry*; D006801:Humans; D016339:Spectrometry, Mass, Fast Atom Bombardment; D014118:Toxins, Biological / Q000097:blood* / Q000737:chemistry / Q000302:isolation & purification; D014511:Uremia / Q000097:blood*
chemical_list: D014118:Toxins, Biological; C026865:uremia middle molecule toxins; D005340:Fibrinogen