title: Molecular cloning and characterization of a lysozyme cDNA from the mole cricket Gryllotalpa orientalis (Orthoptera: Gryllotalpidae).
abstract: A full-length lysozyme cDNA from Gryllotalpa orientalis was cloned and sequenced. The deduced amino acid sequence of the lysozyme protein was 143 amino acids in length, with a calculated molecular mass of 15.84 kDa and an isoelectric point of 4.74. Sequence motifs, together with alignment and phylogenetic results, confirmed that G. orientalis lysozyme belongs to the C (chicken)-type lysozyme family of proteins. The protein sequence of lysozyme from G. orientalis showed high identity to that of Drosophila melanogaster (51.7 %); however, in contrast to D. melanogaster lysozyme, G. orientalis lysozyme was immune inducible and expressed in a wide range of tissues. Expression of G. orientalis lysozyme mRNA was highest at 8 h post-infection and subsequently decreased with time after bacterial infection. We also expressed G. orientalis lysozyme protein in vitro using the pET expression system. Compared with the negative control, over-expressed G. orientalis lysozyme showed antimicrobial activity against Gram-negative bacteria Escherichia coli and Gram-positive bacteria Bacillus subtilis by radial diffusion assay, with minimal inhibitory concentration values of 30.3 and 7.55 µM, respectively. These results indicate that G. orientalis lysozyme may have stronger antimicrobial activity than other lysozymes against a broad range of microorganisms.
authors.affiliation: Department of Applied Biology, Environment Friendly Agriculture Center, College of Agriculture and Life Science, Kangwon National University, Chuncheon, 200-701, Korea.
authors.forename: Hyojung
authors.initials: H
authors.lastname: Kwon
authors.forename: Kyeongrin
authors.initials: K
authors.lastname: Bang
authors.forename: Minsup
authors.initials: M
authors.lastname: Lee
authors.forename: Saeyoull
authors.initials: S
authors.lastname: Cho
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004331:Drosophila melanogaster / Q000201:enzymology; D004926:Escherichia coli / Q000187:drug effects; D006135:Gryllidae / Q000201:enzymology*; D019476:Insect Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009113:Muramidase / Q000235:genetics* / Q000494:pharmacology; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D000890:Anti-Infective Agents; D018076:DNA, Complementary; D019476:Insect Proteins; D012333:RNA, Messenger; D009113:Muramidase