2 research outputs found
Stimulated Emission Depletion Nanoscopy Reveals Time-Course of Human Immunodeficiency Virus Proteolytic Maturation
Concomitant with
human immunodeficiency virus type 1 (HIV-1) budding
from a host cell, cleavage of the structural Gag polyproteins by the
viral protease (PR) triggers complete remodeling of virion architecture.
This maturation process is essential for virus infectivity. Electron
tomography provided structures of immature and mature HIV-1 with a
diameter of 120–140 nm, but information about the sequence
and dynamics of structural rearrangements is lacking. Here, we employed
super-resolution STED (stimulated emission depletion) fluorescence
nanoscopy of HIV-1 carrying labeled Gag to visualize the virion architecture.
The incomplete Gag lattice of immature virions was clearly distinguishable
from the condensed distribution of mature protein subunits. Synchronized
activation of PR within purified particles by photocleavage of a caged
PR inhibitor enabled time-resolved <i>in situ</i> observation
of the induction of proteolysis and maturation by super-resolution
microscopy. This study shows the rearrangement of subviral structures
in a super-resolution light microscope over time, outwitting phototoxicity
and fluorophore bleaching through synchronization of a biological
process by an optical switch
Specific Inhibitors of HIV Capsid Assembly Binding to the C‑Terminal Domain of the Capsid Protein: Evaluation of 2‑Arylquinazolines as Potential Antiviral Compounds
Assembly
of human immunodeficiency virus (HIV-1) represents an
attractive target for antiretroviral therapy which is not exploited
by currently available drugs. We established high-throughput screening
for assembly inhibitors based on competition of small molecules for
the binding of a known dodecapeptide assembly inhibitor to the C-terminal
domain of HIV-1 CA (capsid). Screening of >70000 compounds from
different
libraries identified 2-arylquinazolines as low micromolecular inhibitors
of HIV-1 capsid assembly. We prepared focused libraries of modified
2-arylquinazolines and tested their capacity to bind HIV-1 CA to compete
with the known peptide inhibitor and to prevent the replication of
HIV-1 in tissue culture. Some of the compounds showed potent binding
to the C-terminal domain of CA and were found to block viral replication
at low micromolar concentrations