Isolation and functional analysis of a 24-residue linear alpha-helical antimicrobial peptide from Korean blackish cicada, Cryptotympana dubia (Homoptera).
A new antimicrobial peptide, cryptonin, was isolated and characterized from the adult Korean blackish cicada, Cryptotympana dubia. It consists of 24 amino acid residues and has a molecular weight of 2,704 Da on mass spectroscopy. The predicted alpha-helical structure analysis and increased helix percent in 40% trifloroethanol of cryptonin suggests that it belongs to the typical linear alpha-helix forming peptide. Binding of the biotin-labeled cryptonin at the surface of E. coli cells and increased influx of propidium iodide in E. coli after cryptonin treatment indicates that it kills microbial cells by binding bacterial cell surfaces and disrupting the cell permeability. Cryptonin showed strong antibacterial (MIC 1.56-25 microg/ml) and antifungal (MIC 3.12-50 microg/ml) activities against tested bacteria and fungi including two antibiotic-resistant bacterial strains; methicilin-resistant S. aureus and vancomycin-resistant Enterococci (MIC 25 microg/ml, each).
Leem
Jae Yoon
JY
Insect Resources Research Center, KRIBB, Daejeon 305-806 [corrected] Korea.
Park
Doo-Sang
DS
Suh
Eun Young
EY
Hur
Jang Hyun
JH
Oh
Hyun-Woo
HW
Park
Ho-Yong
HY
D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002463:Cell Membrane Permeability; D002942:Circular Dichroism; D006430:Hemiptera / Q000737:chemistry / Q000378:metabolism*; D053878:Hemolytic Agents / Q000032:analysis; D018613:Microscopy, Confocal; D051381:Rats
D023181:Antimicrobial Cationic Peptides; D053878:Hemolytic Agents