title: Antiviral activity of a serine protease from the digestive juice of Bombyx mori larvae against nucleopolyhedrovirus.
abstract: A protein showing strong antiviral activity against Bombyx mori nucleopolyhedrovirus (BmNPV) was purified from the digestive juice of B. mori larvae. The molecular mass of this protein was 24271 Da. Partial N-terminal amino acid sequence of the protein was determined and cDNA was cloned based on the amino acid sequence. A homology search of the deduced amino acid sequence of the cDNA showed 94% identity with B. mori serine protease so the protein was designated B. mori serine protease-2 (BmSP-2). Analysis of BmSP-2 gene expression showed that this gene is expressed in the midgut but not in other tissues. In addition, BmSP-2 gene was shown to not be expressed in the molting and wandering stages, indicating that the gene is hormonally regulated. Our results suggest that BmSP-2, an insect digestive enzyme, can be a potential antiviral factor against BmNPV at the initial site of viral infection.
authors.affiliation: Innate Immunity Laboratory, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, 305-8634 Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakazawa
authors.forename: Eiko
authors.initials: E
authors.lastname: Tsuneishi
authors.forename: Kangayam M
authors.initials: KM
authors.lastname: Ponnuvel
authors.forename: Seiichi
authors.initials: S
authors.lastname: Furukawa
authors.forename: Ai
authors.initials: A
authors.lastname: Asaoka
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Tanaka
authors.forename: Jun
authors.initials: J
authors.lastname: Ishibashi
authors.forename: Minoru
authors.initials: M
authors.lastname: Yamakawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology*; D012831:Bombyx / Q000201:enzymology* / Q000821:virology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression; D007814:Larva / Q000201:enzymology / Q000821:virology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017924:Nucleopolyhedroviruses / Q000187:drug effects*; D016415:Sequence Alignment; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000998:Antiviral Agents; D018076:DNA, Complementary; D012697:Serine Endopeptidases