Isolation and Characterization of a Defensin-Like Peptide (Coprisin) from the Dung Beetle, Copris tripartitus.
The antibacterial activity of immune-related peptides, identified by a differential gene expression analysis, was investigated to suggest novel antibacterial peptides. A cDNA encoding a defensin-like peptide, Coprisin, was isolated from bacteria-immunized dung beetle, Copris tripartitus, by using differential dot blot hybridization. Northern blot analysis showed that Coprisin mRNA was up-regulated from 4 hours after bacteria injection and its expression level was reached a peak at 16 hours. The deduced amino acid sequence of Coprisin was composed of 80 amino acids with a predicted molecular weight of 8.6 kDa and a pI of 8.7. The amino acid sequence of mature Coprisin was found to be 79.1% and 67.4% identical to those of defensin-like peptides of Anomala cuprea and Allomyrina dichotoma, respectively. We also investigated active sequences of Coprisin by using amino acid modification. The result showed that the 9-mer peptide, LLCIALRKK-NH(2), exhibited potent antibacterial activities against Escherichia coli and Staphylococcus aureus.
Hwang
Jae-Sam
JS
National Academy of Agricultural Science, RDA, Suwon 441-707, South Korea.
Lee
Juneyoung
J
Kim
Yeon-Ju
YJ
Bang
Hea-Son
HS
Yun
Eun-Young
EY
Kim
Seong-Ryul
SR
Suh
Hwa-Jin
HJ
Kang
Bo-Ram
BR
Nam
Sung-Hee
SH
Jeon
Jae-Pil
JP
Kim
Iksoo
I
Lee
Dong Gun
DG