Structure-activity relationship of an antibacterial peptide, maculatin 1.1, from the skin glands of the tree frog, Litoria genimaculata.
Maculatin 1.1 (Mac) is a cationic antibacterial peptide isolated from the dorsal glands of the tree frog, Litoria genimaculata, and has a sequence of GLFGVLAKVAAHVVPAIAEHF-NH2. A short peptide lacking the N-terminal two residues of Mac was reported to have no activity. To investigate the structure-activity relationship in detail, several analogs and related short peptides of Mac were synthesized. CD measurement showed that all the peptides took more or less an alpha-helical structure in the presence of anionic lipid vesicles. Analogs which are more basic than Mac had strong antibacterial and hemolytic activities, while short peptides lacking one or two terminal residues exhibited weak or no activity. Outer and inner membrane permeabilization activities of the peptides were also reduced with shortening of the peptide chain. These results indicate that the entire chain length of Mac is necessary for full activity, and the basicity of the peptides greatly affects the activity.
Department of Materials Science, Graduate School of Science and Technology, Nagasaki University, Nagasaki 852- 8521, Japan. tanido@net.nagasaki-u.ac.jp
Takuro
T
Niidome
Kazuhisa
K
Kobayashi
Hiromi
H
Arakawa
Tomomitsu
T
Hatakeyama
Haruhiko
H
Aoyagi
D000595:Amino Acid Sequence; D029845:Amphibian Proteins / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D002463:Cell Membrane Permeability; D002942:Circular Dichroism; D005452:Fluoresceins / Q000378:metabolism; D006461:Hemolysis / Q000187:drug effects; D008081:Liposomes / Q000378:metabolism; D008969:Molecular Sequence Data; D011898:Ranidae; D012867:Skin / Q000737:chemistry*; D013329:Structure-Activity Relationship
D029845:Amphibian Proteins; D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D005452:Fluoresceins; D008081:Liposomes; C113499:maculatin-1.1 protein, Litoria; C007740:fluorexon