Cyclic Peptide Inhibitors of HIV-1 Capsid-Human Lysyl-tRNA Synthetase Interaction

Abstract

The human immunodeficiency virus type 1 (HIV-1) capsid protein (CA) plays a critical role in the viral life cycle. The C-terminal domain (CTD) of CA binds to human lysyl-tRNA synthetase (hLysRS), and this interaction facilitates packaging of host cell tRNALys,3, which serves as the primer for reverse transcription. Here, we report the library synthesis, high-throughput screening, and identification of cyclic peptides (CPs) that bind HIV-1 CA. Scrambling or single-residue changes of the selected peptide sequences eliminated binding, suggesting a sequence-specific mode of interaction. Two peptides (CP2 and CP4) subjected to detailed analysis also inhibited hLysRS/CA interaction in vitro. Nuclear magnetic resonance spectroscopy and mutagenesis studies revealed that both CPs bind to a site proximal to helix 4 of the CA-CTD, which is the known site of hLysRS interaction. These results extend the current repertoire of CA-binding molecules to a new class of peptides targeting a novel site with potential for development into novel antiviral agents.

Macrocyclization Reactions: The Importance of Conformational, Configurational, and Template-Induced Preorganization

“…88 The letter n denotes the number of monomers in the monocyclic polymer. RGD β-lactam peptidomimetics that induce differential gene expression in human endothelial cells, 49 G-quadruplex ligands for anticancer therapeutics, 50 the excellent tumor uptake and pharmacokinetics of 64 Cu-labeled cyclic RGD peptide dimers with Gly and PEG linkers, 51 macrocyclic lactams as potent Hsp90 inhibitors with excellent tumor exposure and extended biomarker activity, 52,53 proteasome inhibitors, 54 inhibitors of HIV-1 capsid-human lysyl-tRNA synthetase, 55 macrocyclic lactams inspired on the skeleton of natural products with anticancer properties, 56 etc. Besides the considered biomedical applications, macrocyclic structures have found important applications in other fields such as chemical analysis 57,58 or nanotechnology.…”

Drug Resistance in Bacteria, Fungi, Malaria, and Cancer

“…There is still tremendous scope for targeting the clinically validated HIV targets (RT, IN, PR, and CCR5) through diverse mechanisms of action, such as RNase H inhibitors , nucleotide-competing RT inhibitors (NcRTIs) (Maga et al 2010), allosteric IN inhibitors, and PR dimerization inhibitors ). These targets include the dimerization initiation site (DIS) of the HIV-1 genomic RNA (Ennifar et al 2013), HIV-1 matrix protein (Zentner et al 2013), HIV-1 capsid (Dewan et al 2012), nuclear import of pre-integration complex (Zhan et al 2010), retroviral nucleocapsid zinc fingers (Vercruysse et al 2012), and many host antiviral restriction factors (Sloan and Wainberg 2013). These targets include the dimerization initiation site (DIS) of the HIV-1 genomic RNA (Ennifar et al 2013), HIV-1 matrix protein (Zentner et al 2013), HIV-1 capsid (Dewan et al 2012), nuclear import of pre-integration complex (Zhan et al 2010), retroviral nucleocapsid zinc fingers (Vercruysse et al 2012), and many host antiviral restriction factors (Sloan and Wainberg 2013).…”

Targeting the HIV RNA Genome: High-Hanging Fruit Only Needs a Longer Ladder

“…The interaction of human lysyl tRNA synthetase (LysRS) with the capsid (CA) domain of the Gag precursor (via its C-terminal domain or CTD) was identified by Kleiman and colleagues, whose related studies elegantly showed that disrupting LysRS synthesis reduced tRNA Lys,3 incorporation into virions its and annealing to the viral RNA genome (Guo et al 2003). With the goal of disrupting LysRS/CA interactions, combinatorial library screening, Dewan et al (2012) have subsequently identified two cyclic peptides (whose clinical application takes advantage of their enhanced resistance to proteolytic degradation) that are active in vitro in the low micromolar range. While the in vivo selectivity of this first-in-class LysRS/CA antagonists has not be demonstrated, it paves the way for development of modified cyclic peptides with improved cell penetration and pharmacokinetic properties.…”