Covalent binding of the natural antimicrobial peptide indolicidin to DNA abasic sites.
Indolicidin is a host defense tridecapeptide that inhibits the catalytic activity of HIV-1 integrase in vitro. Here we have elucidated its mechanism of integrase inhibition. Using crosslinking and mass spectrometric footprinting approaches, we found that indolicidin interferes with formation of the catalytic integrase-DNA complex by directly binding DNA. Further characterization revealed that the peptide forms covalent links with abasic sites. Indolicidin crosslinks single- or double-stranded DNAs and various positions of the viral cDNA with comparable efficiency. Using truncated and chemically modified peptides, we show that abasic site crosslinking is independent of the PWWP motif but involves the indolicidin unique lysine residue and the N- and C- terminal NH2 groups. Because indolicidin can also inhibit topoisomerase I, we believe that multiple actions at the level of DNA might be a common property of antimicrobial peptides.
Marchand
Christophe
C
Laboratory of Molecular Pharmacology, Center for Cancer Research, Building 37, Room 5068, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4255, USA.
Krajewski
Krzysztof
K
Lee
Hsiu-Fang
HF
Antony
Smitha
S
Johnson
Allison A
AA
Amin
Ronak
R
Roller
Peter
P
Kvaratskhelia
Mamuka
M
Pommier
Yves
Y
D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D001665:Binding Sites; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004264:DNA Topoisomerases, Type I / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000378:metabolism; D019427:HIV Integrase / Q000378:metabolism; D008239:Lysine / Q000737:chemistry; D011485:Protein Binding; D012545:Schiff Bases / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D023181:Antimicrobial Cationic Peptides; D004277:DNA, Single-Stranded; C515555:RIN 25 peptide; D012545:Schiff Bases; C073143:indolicidin; D004247:DNA; D019427:HIV Integrase; D004264:DNA Topoisomerases, Type I; D008239:Lysine