Bactericidal antisense effects of peptide-PNA conjugates.
Antisense peptide nucleic acids (PNAs) can specifically inhibit Escherichia coli gene expression and growth and hold promise as anti-infective agents and as tools for microbial functional genomics. Here we demonstrate that chemical modification improves the potency of standard PNAs. We show that 9- to 12-mer PNAs, especially when attached to the cell wall/membrane-active peptide KFFKFFKFFK, provide improvements in antisense potency in E. coli amounting to two orders of magnitude while retaining target specificity. Peptide-PNA conjugates targeted to ribosomal RNA (rRNA) and to messenger RNA (mRNA) encoding the essential fatty acid biosynthesis protein Acp prevented cell growth. The anti-acpP PNA at 2 microM concentration cured HeLa cell cultures noninvasively infected with E. coli K12 without any apparent toxicity to the human cells. These results indicate that peptides can be used to carry antisense PNA agents into bacteria. Such peptide-PNA conjugates open exciting possibilities for anti-infective drug development and provide new tools for microbial genetics.
Center for Genomics Research, Karolinska Institute, Berzelius väg 37, 171 77, Stockholm, Sweden. liam.good@cgr.ki.se
L
L
Good
S K
SK
Awasthi
R
R
Dryselius
O
O
Larsson
P E
PE
Nielsen
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000378:metabolism*; D001483:Base Sequence; D002455:Cell Division; D003001:Cloning, Molecular; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000378:metabolism; D017930:Genes, Reporter; D016680:Genome, Bacterial; D006367:HeLa Cells; D006801:Humans; D007763:Lac Operon; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016376:Oligonucleotides, Antisense / Q000737:chemistry*; D020135:Peptide Nucleic Acids / Q000737:chemistry* / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors
D000900:Anti-Bacterial Agents; D016376:Oligonucleotides, Antisense; D020135:Peptide Nucleic Acids; D010455:Peptides; D012333:RNA, Messenger