title: Expression and characterization of the N-terminal half of antistasin, an anticoagulant protein derived from the leech Haementeria officinalis.
abstract: Antistasin, a 15-kDa anticoagulant protein isolated from the salivary glands of the Mexican leech Haementeria officinalis, has been shown to be a potent inhibitor of factor Xa in the blood coagulation cascade. Antistasin possesses a twofold internal homology between the N- and C-terminal halves of the molecule, suggesting a gene duplication event in the evolution of the antistasin gene. This structural feature also suggests that either or both halves of the protein may possess biological activity if expressed as separate domains. Because the N-terminal domain contains a factor Xa P1-reactive site, we chose to express this domain in an insect cell baculovirus expression system. Characterization of this recombinant half antistasin molecule reveals that the N-terminal domain inhibits factor Xa in vitro, with a K(i) of 1.7 nM.
authors.affiliation: Department of Cellular and Molecular Biology, Merck Sharp & Dohme Research Laboratories, Rahway, New Jersey 07065.
authors.forename: L O
authors.initials: LO
authors.lastname: Palladino
authors.forename: J S
authors.initials: JS
authors.lastname: Tung
authors.forename: C
authors.initials: C
authors.lastname: Dunwiddie
authors.forename: K
authors.initials: K
authors.lastname: Alves
authors.forename: A B
authors.initials: AB
authors.lastname: Lenny
authors.forename: C
authors.initials: C
authors.lastname: Przysiecki
authors.forename: D
authors.initials: D
authors.lastname: Lehman
authors.forename: E
authors.initials: E
authors.lastname: Nutt
authors.forename: G C
authors.initials: GC
authors.lastname: Cuca
authors.forename: S W
authors.initials: SW
authors.lastname: Law
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000925:Anticoagulants / Q000302:isolation & purification / Q000494:pharmacology; D016367:Baculoviridae / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D065427:Factor Xa Inhibitors; D015870:Gene Expression; D007447:Invertebrate Hormones / Q000235:genetics* / Q000302:isolation & purification / Q000494:pharmacology; D007865:Leeches / Q000235:genetics*; D008969:Molecular Sequence Data
chemical_list: D000925:Anticoagulants; D065427:Factor Xa Inhibitors; D007447:Invertebrate Hormones; C053155:antistasin; D004247:DNA