3 research outputs found
Structural and Functional Characterization of Indane-Core CD4-Mimetic Compounds Substituted with Heterocyclic Amines
The human immunodeficiency virus (HIV-1) envelope glycoprotein
(Env) trimer on the virion surface interacts with the host receptors,
CD4 and CCR5/CXCR4, to mediate virus entry into the target cell. CD4-mimetic
compounds (CD4mcs) bind the gp120 Env, block CD4 binding, and inactivate
Env. Previous studies suggested that a C(5)-methylamino methyl moiety
on a lead CD4mc, BNM-III-170, contributed to its antiviral potency.
By replacing the C(5) chain with differentially substituted pyrrolidine,
piperidine, and piperazine ring systems, guided by structural and
computational analyses, we found that the 5-position of BNM-III-170
is remarkably tolerant of a variety of ring sizes and substitutions,
both in regard to antiviral activity and sensitization to humoral
responses. Crystallographic analyses of representative analogues from
the pyrrolidine series revealed the potential for 5-substituents to
hydrogen bond with gp120 Env residue Thr 283. Further optimization
of these interactions holds promise for the development of CD4mcs
with greater potency
Small-Molecule CD4-Mimics: Structure-Based Optimization of HIVā1 Entry Inhibition
The
optimization, based on computational, thermodynamic, and crystallographic
data, of a series of small-molecule ligands of the Phe43 cavity of
the envelope glycoprotein gp120 of human immunodeficiency virus (HIV)
has been achieved. Importantly, biological evaluation revealed that
the small-molecule CD4 mimics (<b>4</b>ā<b>7</b>) inhibit HIV-1 entry into target cells with both significantly higher
potency and neutralization breadth than previous congeners, while
maintaining high selectivity for the target virus. Their binding mode
was characterized via thermodynamic and crystallographic studies
Structure-Based Design and Synthesis of an HIVā1 Entry Inhibitor Exploiting Xāray and Thermodynamic Characterization
The design, synthesis, thermodynamic and crystallographic
characterization
of a potent, broad spectrum, second-generation HIV-1 entry inhibitor
that engages conserved carbonyl hydrogen bonds within gp120 has been
achieved. The optimized antagonist exhibits a submicromolar binding
affinity (110 nM) and inhibits viral entry of clade B and C viruses
(IC<sub>50</sub> geometric mean titer of 1.7 and 14.0 Ī¼M, respectively),
without promoting CD4-independent viral entry. The thermodynamic signatures
indicate a binding preference for the (<i>R</i>,<i>R</i>)- over the (<i>S</i>,<i>S</i>)-enantiomer.
The crystal structure of the small-molecule/gp120 complex reveals
the displacement of crystallographic water and the formation of a
hydrogen bond with a backbone carbonyl of the bridging sheet. Thus,
structure-based design and synthesis targeting the highly conserved
and structurally characterized CD4āgp120 interface is an effective
tactic to enhance the neutralization potency of small-molecule HIV-1
entry inhibitors