title: Molecular cloning and characterization of a serine proteinase inhibitor from Trichinella spiralis.
abstract: We produced a recombinant protein from a cDNA library from muscle larvae of Trichinella spiralis which had proteinase inhibitory activity. The predicted amino acid sequence of the clone had an identity of only 30% to the serine proteinase inhibitors (serpins) from Caenorhabditis elegans or Brugia malayi. At the putative reactive region, however, the identity was about 50%. The recombinant protein expressed in Escherichia coli inhibited 82% of the activity of the serine proteinase (trypsin). Stage-specific expression of this protein was suggested from the following experiments. Antibody against the recombinant protein could stain proteins migrating at about 42 kDa (which is the expected size from the sequence) in crude extracts from newborn larvae and 18-day post-infection (p.i.) muscle larvae, but it failed to stain any proteins in crude extracts from 30-day p.i. muscle larvae. Production of mRNA transcript for the serpin gene was restricted largely to the newborn larvae and to 18-day p.i. muscle larvae. The antibody reacted with the stichocytes of the larvae at 18 days p.i., but did not react with the muscle larvae at 24 days and 30 days p.i.
authors.affiliation: Department of Parasitology, Gifu University School of Medicine, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Nagano
authors.forename: Z
authors.initials: Z
authors.lastname: Wu
authors.forename: T
authors.initials: T
authors.lastname: Nakada
authors.forename: A
authors.initials: A
authors.lastname: Matsuo
authors.forename: Y
authors.initials: Y
authors.lastname: Takahashi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000947:Antigens, Helminth / Q000032:analysis; D001483:Base Sequence; D015153:Blotting, Western; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015801:Helminth Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D007150:Immunohistochemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000737:chemistry / Q000469:parasitology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D018510:RNA, Helminth / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015842:Serine Proteinase Inhibitors / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D017160:Trichinella spiralis / Q000737:chemistry / Q000235:genetics*; D014235:Trichinellosis / Q000469:parasitology; D014357:Trypsin / Q000378:metabolism; D014361:Trypsin Inhibitors; D000516:alpha-Amylases / Q000037:antagonists & inhibitors
chemical_list: C437643:11-1 protein, Trichinella spiralis; D000947:Antigens, Helminth; D015801:Helminth Proteins; D010940:Plant Proteins; D018510:RNA, Helminth; D011994:Recombinant Proteins; D015842:Serine Proteinase Inhibitors; D014361:Trypsin Inhibitors; D000516:alpha-Amylases; D014357:Trypsin