title: Circulating human pregnancy-associated plasma protein-A is disulfide-bridged to the proform of eosinophil major basic protein.
abstract: A previously unrecognized association between pregnancy-associated plasma protein-A (PAPP-A) and the proform of eosinophil major basic protein (proMBP) is demonstrated. PAPP-A isolated from pooled pregnancy serum is shown to be a disulfide-bridged complex with proMBP (PAPP-A/proMBP) in which the subunits of the constituents are present in a 1:1 molar ratio. The results are the outcome of analysis of tryptic and CNBr/tryptic peptides from PAPP-A/proMBP, sequence analysis of intact and reduced and carboxymethylated PAPP-A/proMBP, and reaction with monoclonal antibodies directed against MBP and its proform. In addition, it is shown that commercial polyclonal anti-PAPP-A is polyspecific, also reacting with MBP.
authors.affiliation: Department of Molecular Biology, University of Aarhus, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Oxvig
authors.forename: O
authors.initials: O
authors.lastname: Sand
authors.forename: T
authors.initials: T
authors.lastname: Kristensen
authors.forename: G J
authors.initials: GJ
authors.lastname: Gleich
authors.forename: L
authors.initials: L
authors.lastname: Sottrup-Jensen
mesh_terms: D000595:Amino Acid Sequence; D001798:Blood Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D003488:Cyanogen Bromide; D004220:Disulfides; D004591:Electrophoresis, Polyacrylamide Gel; D047091:Eosinophil Granule Proteins; D004804:Eosinophils; D005260:Female; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000302:isolation & purification; D011247:Pregnancy / Q000097:blood*; D011266:Pregnancy-Associated Plasma Protein-A / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D011485:Protein Binding; D011498:Protein Precursors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012260:Ribonucleases; D014357:Trypsin
chemical_list: D001798:Blood Proteins; D004220:Disulfides; D047091:Eosinophil Granule Proteins; D010446:Peptide Fragments; D011498:Protein Precursors; D012260:Ribonucleases; D014357:Trypsin; D011266:Pregnancy-Associated Plasma Protein-A; D003488:Cyanogen Bromide