title: Molecular engineering of RANTES peptide mimetics with potent anti-HIV-1 activity.
abstract: The chemokine receptor CCR5 is utilized as a critical coreceptor by most primary HIV-1 strains. While the lack of structural information on CCR5 has hampered the rational design of specific inhibitors, mimetics of the chemokines that naturally bind CCR5 can be molecularly engineered. We used a structure-guided approach to design peptide mimetics of the N-loop and β1-strand regions of regulated on activation normal T-cell-expressed and secreted (RANTES)/CCL5, which contain the primary molecular determinants of HIV-1 blockade. Rational modifications were sequentially introduced into the N-loop/β1-strand sequence, leading to the generation of mimetics with potent activity against a broad spectrum of CCR5-specific HIV-1 isolates (IC(50) range: 104-640 nM) but lacking activity against CXCR4-specific HIV-1 isolates. Functional enhancement was initially achieved with the stabilization of the N loop in the β-extended conformation adopted in full-length RANTES, as confirmed by nuclear magnetic resonance (NMR) analysis. However, the most dramatic increase in antiviral potency resulted from the engraftment of an in silico-optimized linker segment designed using de novo structure-prediction algorithms to stabilize the C-terminal α-helix and experimentally validated by NMR. Our mimetics exerted CCR5-antagonistic effects, demonstrating that the antiviral and proinflammatory functions of RANTES can be uncoupled. RANTES peptide mimetics provide new leads for the development of safe and effective HIV-1 entry inhibitors.
authors.affiliation: Unit of Human Virology, Department of Biological and Technological Research (DIBIT), San Raffaele Scientific Institute, Milan, Italy. plusso@niaid.nih.gov
authors.forename: Paolo
authors.initials: P
authors.lastname: Lusso
authors.forename: Luca
authors.initials: L
authors.lastname: Vangelista
authors.forename: Raffaello
authors.initials: R
authors.lastname: Cimbro
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Secchi
authors.forename: Francesca
authors.initials: F
authors.lastname: Sironi
authors.forename: Renato
authors.initials: R
authors.lastname: Longhi
authors.forename: Marina
authors.initials: M
authors.lastname: Faiella
authors.forename: Ornella
authors.initials: O
authors.lastname: Maglio
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Pavone
mesh_terms: D000595:Amino Acid Sequence; D019380:Anti-HIV Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D040761:Biomimetic Materials / Q000138:chemical synthesis*; D065100:CCR5 Receptor Antagonists; D018946:Chemokine CCL5 / Q000138:chemical synthesis*; D002633:Chemotaxis / Q000187:drug effects; D015497:HIV-1 / Q000187:drug effects*; D057927:Hydrophobic and Hydrophilic Interactions; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000138:chemical synthesis* / Q000494:pharmacology; D011487:Protein Conformation; D015202:Protein Engineering; D015398:Signal Transduction / Q000187:drug effects; D013329:Structure-Activity Relationship; D048051:p38 Mitogen-Activated Protein Kinases / Q000187:drug effects
chemical_list: D019380:Anti-HIV Agents; D065100:CCR5 Receptor Antagonists; D018946:Chemokine CCL5; D010455:Peptides; D048051:p38 Mitogen-Activated Protein Kinases