A synthetic peptide from the human immunodeficiency virus type-1 integrase exhibits coiled-coil properties and interferes with the in vitro integration activity of the enzyme. Correlated biochemical and spectroscopic results.
Integration of the human immunodeficiency virus (HIV-1) DNA into the host genome is catalysed by a virus-encoded protein integrase. Here, we report some of the structural and functional properties of two synthetic peptides: integrase-(147-175)-peptide reproducing the residues 147-175 (SQGVVESMNKELK159KIIGQVRDQAEHLKTAY) of the HIV-1 integrase, and [Pro159] integrase-(147-175)-peptide where the lysine 159 is substituted for a proline. Circular dichroism revealed that both peptides are mostly under unordered conformation in aqueous solution, contrasting with the alpha-helix exhibited by residues 147-175 in the protein crystal structure. In a weak alpha-helix-promoting environment, integrase-(147-175)-peptide self-associated into stable coiled-coil oligomers, while [Pro159] integrase-(147-175)-peptide did not. This property was further confirmed by cross-linking experiments. In our in vitro experiments, only integrase-(147-175)-peptide was able to reduce the integration activity of the enzyme. We propose that the inhibitory activity shown by integrase-(147-175)-peptide is dependent on its ability to bind to its counterpart in integrase through a peptide-protein coiled-coil structure disturbing the catalytic properties of the enzyme.
Sourgen
F
F
Département de Biologie et Pharmacologie Structurales, CNRS URA 147, Institut Gustave Roussy, Villejuif, France.
Maroun
R G
RG
Frère
V
V
Bouziane
M
M
Auclair
C
C
Troalen
F
F
Fermandjian
S
S
D000595:Amino Acid Sequence; D002942:Circular Dichroism; D003432:Cross-Linking Reagents; D019427:HIV Integrase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015497:HIV-1 / Q000201:enzymology / Q000235:genetics; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000235:genetics; D017433:Protein Structure, Secondary
D003432:Cross-Linking Reagents; D010446:Peptide Fragments; D019427:HIV Integrase