4 research outputs found
Catalytic Enantioselective Allyl–Allyl Cross-Coupling with a Borylated Allylboronate
Catalytic enantioselective allyl–allyl cross-coupling of a borylated allylboronate reagent gives versatile borylated chiral 1,5-hexadienes. These compounds may be manipulated in a number of useful ways to give functionalized chiral building blocks for asymmetric synthesis
Selectivity Determination of a Small Molecule Chemical Probe Using Protein Microarray and Affinity Capture Techniques
Small molecule selectivity is an
essential component of candidate
drug selection and target validation. New technologies are required
to better understand off-target effects, with particular emphasis
needed on broad protein profiling. Here, we describe the use of a
tritiated chemical probe and a 9000 human protein microarray to discern
the binding selectivity of an inhibitor of the mRNA decapping scavenger
enzyme DcpS. An immobilized m<sup>7</sup>GTP resin was also used to
assess the selectivity of a DcpS inhibitor against mRNA cap-associated
proteins in whole cell extracts. These studies confirm the exquisite
selectivity of diaminoquinazoline DcpS inhibitors, and highlight the
utility of relatively simple protein microarray and affinity enrichment
technologies in drug discovery and chemical biology
Covalent Enzyme Inhibition through Fluorosulfate Modification of a Noncatalytic Serine Residue
Irreversible enzyme
inhibitors and covalent chemical biology probes
often utilize the reaction of a protein cysteine residue with an appropriately
positioned electrophile (<i>e.g.</i>, acrylamide) on the
ligand template. However, cysteine residues are not always available
for site-specific protein labeling, and therefore new approaches are
needed to expand the toolkit of appropriate electrophiles (“warheads”)
that target alternative amino acids. We previously described the rational
targeting of tyrosine residues in the active site of a protein (the
mRNA decapping scavenger enzyme, DcpS) using inhibitors armed with
a sulfonyl fluoride electrophile. These inhibitors subsequently enabled
the development of clickable probe technology to measure drug-target
occupancy in live cells. Here we describe a fluorosulfate-containing
inhibitor (aryl fluorosulfate probe (FS-p1)) with excellent chemical
and metabolic stability that reacts selectively with a noncatalytic
serine residue in the same active site of DcpS as confirmed by peptide
mapping experiments. Our results suggest that noncatalytic serine
targeting using fluorosulfate electrophilic warheads could be a suitable
strategy for the development of covalent inhibitor drugs and chemical
probes
Design of Potent mRNA Decapping Scavenger Enzyme (DcpS) Inhibitors with Improved Physicochemical Properties To Investigate the Mechanism of Therapeutic Benefit in Spinal Muscular Atrophy (SMA)
The C-5 substituted 2,4-diaminoquinazoline
RG3039 (compound <b>1</b>), a member of a chemical series that
was identified and
optimized using an SMN2 promoter screen, prolongs survival and improves
motor function in a mouse model of spinal muscular atrophy (SMA).
It is a potent inhibitor of the mRNA decapping scavenger enzyme (DcpS),
but the mechanism whereby DcpS inhibition leads to therapeutic benefit
is unclear. Compound <b>1</b> is a dibasic lipophilic molecule
that is predicted to accumulate in lysosomes. To understand if the <i>in vivo</i> efficacy is due to DcpS inhibition or other effects
resulting from the physicochemical properties of the chemotype, we
undertook structure based molecular design to identify DcpS inhibitors
with improved physicochemical properties. Herein we describe the design,
synthesis, and <i>in vitro</i> pharmacological characterization
of these DcpS inhibitors along with the <i>in vivo</i> mouse
CNS PK profile of PF-DcpSi (compound <b>24</b>), one of the
analogs found to be efficacious in SMA mouse model