title: Isolation and amino acid sequences of two Kunitz-type protease inhibitors from the sea anemone Anthopleura aff. xanthogrammica.
abstract: Two protease inhibitors (AXPI-I and -II) were isolated from the sea anemone Anthopleura aff. xanthogrammica by a combination of acetone precipitation, gel filtration on Sephadex G-75, cation-exchange fast protein liquid chromatography (FPLC) on Mono S and reverse-phase HPLC on TSKgel ODS-120T. Both inhibitors are basic polypeptides, and their amino acid compositions are characterized by the presence of six half-Cys residues and the absence of Met and Trp. They are potently active against trypsin; inhibition of other serine proteases (alpha-chymotrypsin and elastase) is also displayed by only AXPI-I. However, the inhibitors show no affinity for metallo-proteases and cysteine proteases. Analyses of the N-terminal portion and enzymatic fragments established their complete amino acid sequences comprising 58 residues. The overall sequence homology and the conserved location of all half-Cys residues confirmed that the A. aff. xanthogrammica inhibitors belong to the Kunitz-type family.
authors.affiliation: Department of Food Science and Technology, Tokyo University of Fisheries, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Minagawa
authors.forename: M
authors.initials: M
authors.lastname: Ishida
authors.forename: K
authors.initials: K
authors.lastname: Shimakura
authors.forename: Y
authors.initials: Y
authors.lastname: Nagashima
authors.forename: K
authors.initials: K
authors.lastname: Shiomi
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D007564:Japan; D008969:Molecular Sequence Data; D010455:Peptides; D010940:Plant Proteins; D012615:Sea Anemones / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid; D014361:Trypsin Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D000596:Amino Acids; C053865:Kunitz-type protease inhibitor, plant; D010455:Peptides; D010940:Plant Proteins; D014361:Trypsin Inhibitors