Pseudin-2: an antimicrobial peptide with low hemolytic activity from the skin of the paradoxical frog.
Four structurally related peptides (pseudins 1-4) with antimicrobial activity were isolated from an extract of the skin of the paradoxical frog Pseudis paradoxa (Pseudidae). Pseudin-2 (GLNALKKVFQGIHEAIKLINNHVQ) was the most abundant peptide (22 nmol/g tissue) and also the most potent (minimum inhibitory concentrations, MIC = 2.5 microM against Escherichia coli, 80 microM against Staphylococcus aureus, and 130 microM against Candida albicans). The concentration of pseudin-2 producing 50% hemolysis of human erythrocytes was >300 microM. Circular dichroism studies showed that the pseudins belong to the class of cationic, amphipathic alpha-helical antimicrobial peptides but their amino acid sequences are not similar to any previously characterized peptides from frog skin. The pseudins do, however, show sequence similarity with a region at the C-terminus of DEFT, a death effector domain-containing protein expressed in mammalian testicular germ cells that is involved in the regulation of apoptosis.
Olson
L
L
Department of Biomedical Sciences, Creighton University Medical School, Omaha, Nebraska 68178-0405, USA.
Soto
A M
AM
Knoop
F C
FC
Conlon
J M
JM
D000595:Amino Acid Sequence; D029845:Amphibian Proteins; D000818:Animals; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001001:Anura; D002176:Candida albicans / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D004268:DNA-Binding Proteins; D053418:Death Domain Receptor Signaling Adaptor Proteins; D004912:Erythrocytes / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry; D016415:Sequence Alignment; D012867:Skin / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects
D029845:Amphibian Proteins; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; C116096:DEDD protein, human; D004268:DNA-Binding Proteins; D053418:Death Domain Receptor Signaling Adaptor Proteins; D047908:Intracellular Signaling Peptides and Proteins; D010455:Peptides; D011506:Proteins; C441477:pseudin-2 protein, Pseudis paradoxa