title: Primary structure of ascidian trypsin inhibitors in the hemolymph of a solitary ascidian, Halocynthia roretzi.
abstract: The amino acid sequences of trypsin inhibitors I and II from the hemolymph of a solitary ascidian, Halocynthia roretzi, were determined after reduction and S-pyridylethylation. The results indicated that inhibitor I consists of a single polypeptide chain with 55 amino acid residues and four intramolecular disulfide bridges, whereas inhibitor II is composed of two polypeptide chains corresponding to a form derived from inhibitor I by cleavage at the Lys16-Met17 bond. Lys16 may be the reactive-site residue of these inhibitors, because carboxypeptidase B treatment destroys most of the inhibitory activity of inhibitor II but not that of inhibitor I.
authors.affiliation: Department of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University.
authors.forename: T
authors.initials: T
authors.lastname: Kumazaki
authors.forename: N
authors.initials: N
authors.lastname: Hoshiba
authors.forename: H
authors.initials: H
authors.lastname: Yokosawa
authors.forename: S
authors.initials: S
authors.lastname: Ishii
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D043424:Carboxypeptidase B; D002268:Carboxypeptidases; D002851:Chromatography, High Pressure Liquid; D004220:Disulfides / Q000032:analysis; D006458:Hemolymph / Q000378:metabolism*; D006868:Hydrolysis; D008969:Molecular Sequence Data; D014361:Trypsin Inhibitors / Q000032:analysis*; D014561:Urochordata / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D004220:Disulfides; D014361:Trypsin Inhibitors; D002268:Carboxypeptidases; D043424:Carboxypeptidase B