title: Bovine factor XIIa inhibitor.
abstract: Bovine factor XIIa inhibitor was purified by an improved method employing affinity for heparin. N-terminal amino acid sequencing revealed a unique sequence without homology to any other known protein sequences. Peptide sequencing, however, showed that a part of the bovine factor XIIa inhibitor was homologous to human C1-inhibitor with a fraction of identical amino acid residues around 70%. Deglycosylation studies and carbohydrate analysis showed the presence of N- and O-linked carbohydrate. Bovine factor XIIa inhibitor did not inhibit plasma kallikrein and trypsin. The reactive site comprised an Arg-Asn bond, and represents the first example of asparagine as a P1' residue in Serpins with well documented inhibitory activity.
authors.affiliation: Department of Molecular Biology and Plant Physiology, University of Aarhu, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Muldbjerg
authors.forename: S
authors.initials: S
authors.lastname: Markussen
authors.forename: S
authors.initials: S
authors.lastname: Magnusson
authors.forename: T
authors.initials: T
authors.lastname: Halkier
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001216:Asparagine; D001665:Binding Sites; D001798:Blood Proteins / Q000737:chemistry* / Q000302:isolation & purification; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D016415:Sequence Alignment
chemical_list: D001798:Blood Proteins; C053635:factor XIIa inhibitor; D001216:Asparagine