IndraLab
Statements
sparser
"We now extend our study to structurally profile USP30s interaction
with a small, covalent, cyanopyrrolidine scaffold-containing inhibitor, USP30-I-1 (patent WO2020212350A1; Mission Therapeutics). xref , xref Covalent inhibitors possess significant advantages over their noncovalent
counterparts, including a more prolonged duration of action and the
formation of more specific and irreversible bonds with their substrates,
enhancing the overall drug efficacy. xref Newer-generation
USP30 inhibitors are therefore likely to harness covalent bond formation
between the compound and protein."
sparser
"The lower IC 50 value observed
for USP30-I-1 in the in vitro work was likely a result
of reduced nonspecific inhibitor occlusion as compared to the cellular
matrix, and a similar phenomenon was observed in our USP30 inh work. xref Rates
of inhibition determined from the Ub-rhodamine cleavage progress curves
( xref B) without
USP30 preincubation were plotted against [ USP30-I-1 ]
( xref B Inset) to
determine k inact / K I (traditional method)."
sparser
"When directly comparing
apo-USP30 to holo-USP30, the majority of the USP30 protein sequence
had no significant differential deuterium uptake in the presence of USP30-I-1 , confirming that, as one may expect upon interaction
of a small-molecule with a much larger protein, binding was restricted
to only a small portion of USP30 itself ( xref A and)."
sparser
"Our mapping
further highlighted the strong interaction of USP30-I-1 with the region encompassing the catalytic Cys77 (highlighted in
magenta in xref B) but also supported the identification of other regions of human
USP30 catalytic domain (highlighted in red) that become solvent protected,
albeit to a much lesser extent."
sparser
"For example, the noncovalent USP7 inhibitor, FT671 (PDB code:), and covalent USP7
inhibitor, FT827 (PDB code:), specifically target the catalytically incompetent
apo-form state in which the switching loop adopts an “in”
conformation. xref A comparison of USP30-I-1 with FT827 reveals that the binding site is broadly similar but
that there are conformational differences in the region accommodating
the catalytic cysteine, the switching loop, and blocking loops 1 and
2 ( xref A,B)."
sparser
"Using these values, the compounds have a similar potency
(0.18 and 0.20 μM –1 s –1 for USP30-I-1 and USP30 inh , respectively), in the case of USP30 inh , the potency is driven by the rate at which the irreversible
complex forms with the initial affinity being lower than that of USP30-I-1 (1.27 μM and 350 nM for USP30-I-1 and USP30 inh , respectively)."
sparser
"Our previous study also employed HDX-MS
and computational docking
to elucidate the molecular architecture and geometry of USP30 complex
formation with the noncovalent inhibitor, USP30 inh . xref Both compounds
interact with the catalytic Cys77, but USP30-I-1 induces
a higher degree of solvent protection than does USP30 inh ."
sparser
"The X-ray structure of human USP30 catalytic domain in complex with
UbPA (PDB code:; Gersch et al., 2017 xref ) was used as the
target receptor for USP30 inh because
there were no inhibitor-bound structures available at that time, which
results in differences in conformation in the switching and blocking
loop regions compared with the structure of USP30 in complex with
the covalent inhibitor, 552 (PDB code:), that was used for USP30-I-1 docking studies."
sparser
"Hence, while both studies indicate that USP30 inh and USP30-I-1 are likely to reside within the thumb-palm cleft, differences in
their HDX-MS profiles suggest that there are differences in their
binding modes, which places USP30 inh closer toward the fingers subdomain compared with the predicted
binding site for USP30-I-1 ( xref E)."
sparser
"In addition, the docking pose of USP30-I-1 agrees with the experimental structures of USP30
in complex with the covalent inhibitors, 552 (PDB code:; unpublished) and
829 (PDB code:; unpublished), in which the switching loop adopts an “in”
conformation, suggesting that it is unlikely USP30-I-1 will occupy a cryptic pocket."
sparser
"HA-Ub-PA was synthesized as outlined previously. xref , xref Methodology for HA-Ub-PA activity-based probe profiling was described
in our previous study on a USP30 noncovalent inhibitor. xref Briefly, SH-SY5Y lysates were incubated for
1 h at 37 °C with either USP30-I-1 or dimethyl sulfoxide
(DMSO) at the indicated concentrations in duplicate."
sparser
"All activity assays were performed in black 384-well plates
in assay buffer (20 mM Tris–HCl, pH 8.0, 150 mM Potassium Glutamate,
0.1 mM TCEP and 0.03% Bovine Gamma Globulin) with a final assay volume
of 20 μL. A concentration of 0.2 nM USP30 [residues 64-502Δ179-216
and 288-305, Viva Biotech (Shanghai) Ltd.] was added and preincubated
with USP30-I-1 for 30 min."