title: Covalent binding of the natural antimicrobial peptide indolicidin to DNA abasic sites.
abstract: 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.
authors.affiliation: Laboratory of Molecular Pharmacology, Center for Cancer Research, Building 37, Room 5068, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4255, USA.
authors.forename: Christophe
authors.initials: C
authors.lastname: Marchand
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Krajewski
authors.forename: Hsiu-Fang
authors.initials: HF
authors.lastname: Lee
authors.forename: Smitha
authors.initials: S
authors.lastname: Antony
authors.forename: Allison A
authors.initials: AA
authors.lastname: Johnson
authors.forename: Ronak
authors.initials: R
authors.lastname: Amin
authors.forename: Peter
authors.initials: P
authors.lastname: Roller
authors.forename: Mamuka
authors.initials: M
authors.lastname: Kvaratskhelia
authors.forename: Yves
authors.initials: Y
authors.lastname: Pommier
mesh_terms: 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
chemical_list: 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