title: A bumblebee (Bombus ignitus) venom serine protease inhibitor that acts as a microbial serine protease inhibitor.
abstract: Serine protease inhibitors from bumblebee venom have been shown to block plasmin activity. In this study, we identified the protein BiVSPI from the venom of Bombus ignitus to be a serine protease inhibitor and an antimicrobial factor. BiVSPI is a 55-amino acid mature peptide with ten conserved cysteine residues and a P1 methionine residue. BiVSPI is expressed in the venom gland and also found in the venom as an 8-kDa peptide. Recombinant BiVSPI that was expressed in baculovirus-infected insect cells exhibited inhibitory activity against chymotrypsin but not trypsin. BiVSPI also inhibited microbial serine proteases, such as subtilisin A (Ki=6.57nM) and proteinase K (Ki=7.11nM). In addition, BiVSPI was shown to bind directly to Bacillus subtilis, Bacillus thuringiensis, and Beauveria bassiana but not to Escherichia coli. Consistent with these results, BiVSPI exhibited antimicrobial activity against Gram-positive bacteria and fungi. These findings provide evidence for a novel serine protease inhibitor in bumblebee venom that has antimicrobial functions.
authors.affiliation: College of Natural Resources and Life Science, Dong-A University, Busan 604-714, Republic of Korea.
authors.forename: Hu
authors.initials: H
authors.lastname: Wan
authors.forename: Bo Yeon
authors.initials: BY
authors.lastname: Kim
authors.forename: Kwang Sik
authors.initials: KS
authors.lastname: Lee
authors.forename: Hyung Joo
authors.initials: HJ
authors.lastname: Yoon
authors.forename: Kyung Yong
authors.initials: KY
authors.lastname: Lee
authors.forename: Byung Rae
authors.initials: BR
authors.lastname: Jin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects / Q000201:enzymology*; D001483:Base Sequence; D001514:Bee Venoms / Q000201:enzymology*; D001516:Bees; D003001:Cloning, Molecular; D005658:Fungi / Q000187:drug effects / Q000201:enzymology*; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D008969:Molecular Sequence Data; D057057:Serine Proteases / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D001514:Bee Venoms; D015842:Serine Proteinase Inhibitors; D057057:Serine Proteases
keywords: Antimicrobial activity; Bombus ignitus; Bumblebee; Serine protease inhibitor; Venom