title: High-performance liquid chromatographic determination of sulfated peptides in human hemofiltrate using a radioactivity monitor.
abstract: Specific labeling of tyrosine sulfate-containing peptides was achieved using a differential iodination approach. In a complex peptide mixture from human hemofiltrate, cold iodination to saturate free iodine binding sites was followed by mild acidic desulfation of tyrosine sulfate and subsequent radioiodination using iodine-125. Reaction steps were controlled by amino acid analysis using o-phthaldialdehyde precolumn derivatization and by spiking with a sulfated cholecystokinin fragment (CCK4-S). Separation of the peptide mixture with RP-HPLC on a C18 column coupled to a radioactivity monitor led to the sensitive (< or = 5 pM) and specific determination of tyrosine sulfate-containing peptides.
authors.affiliation: Niedersächsisches Institut für Peptid-Forschung GmbH, Hannover, Germany.
authors.forename: A G
authors.initials: AG
authors.lastname: Schepky
authors.forename: P
authors.initials: P
authors.lastname: Schulz-Knappe
authors.forename: W G
authors.initials: WG
authors.lastname: Forssmann
mesh_terms: D000596:Amino Acids / Q000097:blood; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000706:statistics & numerical data; D006440:Hemofiltration; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007457:Iodine Radioisotopes; D007553:Isotope Labeling; D010455:Peptides / Q000097:blood*; D012844:Sincalide / Q000097:blood; D013431:Sulfates / Q000097:blood*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000097:blood / Q000737:chemistry
chemical_list: D000596:Amino Acids; D007457:Iodine Radioisotopes; D010455:Peptides; D013431:Sulfates; C005662:tyrosine O-sulfate; D014443:Tyrosine; D012844:Sincalide