5 research outputs found
气候统计分析方法及其应用-1
A 26-residue peptide
BimBH3 binds indiscriminately to multiple
oncogenic Bcl2 proteins that regulate apoptosis of cancer cells. Specific
inhibition of the BimBH3-Bcl2A1 protein–protein interaction
was obtained <i>in vitro</i> and in cancer cells by shortening
the peptide to 14 residues, inserting two cyclization constraints
to stabilize a water-stable α-helix, and incorporating an N-terminal
acrylamide electrophile for selective covalent bonding to Bcl2A1.
Mass spectrometry of trypsin-digested bands on electrophoresis gels
established covalent bonding of an electrophilic helix to just one
of the three cysteines in Bcl2A1, the one (Cys55) at the BimBH3-Bcl2A1
protein–protein interaction interface. Optimizing the helix-inducing
constraints and the sequence subsequently enabled electrophile removal
without loss of inhibitor potency. The bicyclic helical peptides were
potent, cell permeable, plasma-stable, dual inhibitors of Bcl2A1 and
Mcl-1 with high selectivity over other Bcl2 proteins. One bicyclic
peptide was shown to inhibit the interaction between a pro-apoptotic
protein (Bim) and either endogenous Bcl2A1 or Mcl-1, to induce apoptosis
of SKMel28 human melanoma cells, and to sensitize them for enhanced
cell death by the anticancer drug etoposide. These approaches look
promising for chemically silencing intracellular proteins
β‑Glucocerebrosidase Modulators Promote Dimerization of β‑Glucocerebrosidase and Reveal an Allosteric Binding Site
β-Glucocerebrosidase
(GCase) mutations cause Gaucher’s
disease and are a high risk factor in Parkinson’s disease.
The implementation of a small molecule modulator is a strategy to
restore proper folding and lysosome delivery of degradation-prone
mutant GCase. Here, we present a potent quinazoline modulator, <b>JZ-4109</b>, which stabilizes wild-type and N370S mutant GCase
and increases GCase abundance in patient-derived fibroblast cells.
We then developed a covalent modification strategy using a lysine
targeted inactivator (<b>JZ-5029</b>) for <i>in vitro</i> mechanistic studies. By using native top-down mass spectrometry,
we located two potentially covalently modified lysines. We obtained
the first crystal structure, at 2.2 Å resolution, of a GCase
with a noniminosugar modulator covalently bound, and were able to
identify the exact lysine residue modified (Lys346) and reveal an
allosteric binding site. GCase dimerization was induced by our modulator
binding, which was observed by native mass spectrometry, its crystal
structure, and size exclusion chromatography with a multiangle light
scattering detector. Finally, the dimer form was confirmed by negative
staining transmission electron microscopy studies. Our newly discovered
allosteric site and observed GCase dimerization provide a new mechanistic
insight into GCase and its noniminosugar modulators and facilitate
the rational design of novel GCase modulators for Gaucher’s
disease and Parkinson’s disease
Implications of Promiscuous Pim-1 Kinase Fragment Inhibitor Hydrophobic Interactions for Fragment-Based Drug Design
We have studied the subtleties of fragment docking and
binding
using data generated in a Pim-1 kinase inhibitor program. Crystallographic
and docking data analyses have been undertaken using inhibitor complexes
derived from an in-house surface plasmon resonance (SPR) fragment
screen, a virtual needle screen, and a de novo designed fragment inhibitor
hybrid. These investigations highlight that fragments that do not
fill their binding pocket can exhibit promiscuous hydrophobic interactions
due to the lack of steric constraints imposed on them by the boundaries
of said pocket. As a result, docking modes that disagree with an observed
crystal structure but maintain key crystallographically observed hydrogen
bonds still have potential value in ligand design and optimization.
This observation runs counter to the lore in fragment-based drug design
that all fragment elaboration must be based on the parent crystal
structure alone
Mitigating hERG Inhibition: Design of Orally Bioavailable CCR5 Antagonists as Potent Inhibitors of R5 HIV-1 Replication
A series of CCR5 antagonists representing the thiophene-3-yl-methyl
ureas were designed that met the pharmacological criteria for HIV-1
inhibition and mitigated a human ether-a-go-go related gene (hERG)
inhibition liability. Reducing lipophilicity was the main design criteria
used to identify compounds that did not inhibit the hERG channel,
but subtle structural modifications were also important. Interestingly,
within this series, compounds with low hERG inhibition prolonged the
action potential duration (APD) in dog Purkinje fibers, suggesting
a mixed effect on cardiac ion channels
Design of Substituted Imidazolidinylpiperidinylbenzoic Acids as Chemokine Receptor 5 Antagonists: Potent Inhibitors of R5 HIV‑1 Replication
The
redesign of the previously reported thiophene-3-yl-methyl urea
series, as a result of potential cardiotoxicity, was successfully
accomplished, resulting in the identification of a novel potent series
of CCR5 antagonists containing the imidazolidinylpiperidinyl scaffold.
The main redesign criteria were to reduce the number of rotatable
bonds and to maintain an acceptable lipophilicity to mitigate hERG
inhibition. The structure–activity relationship (SAR) that
was developed was used to identify compounds with the best pharmacological
profile to inhibit HIV-1. As a result, five advanced compounds, <b>6d</b>, <b>6e</b>, <b>6i</b>, <b>6h</b>, and <b>6k</b>, were further evaluated for receptor selectivity, antiviral
activity against CCR5 using (R5) HIV-1 clinical isolates, and in vitro
and in vivo safety. On the basis of these results, <b>6d</b> and <b>6h</b> were selected for further development