Mechanistic Insights into GTP Hydrolysis by the RhoA Protein: Catalytic Impact of Glutamine Tautomerism
ACS Catalysis,
Год журнала:
2025,
Номер
unknown, С. 4415 - 4428
Опубликована: Фев. 27, 2025
We
present
a
systematic
evaluation
of
different
possible
reaction
mechanisms
for
GTP
hydrolysis
in
RhoA,
member
the
Ras
superfamily
enzymes
that
uses
this
to
switch
from
an
active
inactive
conformation.
These
are
activated
by
presence
GTPase
activating
protein
(or
GAP)
forms
intimate
complex
with
residues
two
proteins
site.
have
explored
multidimensional
reactional
free
energy
landscape
site
formed
RhoA
and
p50RhoGAP.
Our
molecular
dynamics
simulations
show
enzyme
p50RhoGAP
establishes
catalytically
important
interactions
phosphate
groups
through
its
so-called
arginine
finger
(Arg85)
also
residue
Gln63.
This
is
key
because
it
not
only
interacts
nucleophilic
water
molecule
but
participates
actively
mechanism.
Adaptive
string
method
using
hybrid
quantum
mechanics/molecular
mechanics
(QM/MM)
potentials
both
tight-binding
density
functional
Hamiltonians
proceeds
formation
metaphosphate
metastable
species.
Mechanistic
proposals
differ
proton
transfer
rearrangements
required
form
inorganic
ion.
discard
solvent-assisted
mechanism
point
participation
Gln63
process
means
side
chain
tautomerism
amide
imide
form.
The
recover
requires
phosphate,
rate-limiting
step
process,
barrier
20.2
kcal
mol–1
at
B3LYPD3/MM
level,
good
agreement
experimentally
derived
value.
amide–imide
could
be
relevant
other
enzymes,
facilitating
events
mechanisms.
Язык: Английский
Catalytic Enantioselective Smiles Rearrangement Enabled by the Directed Evolution of P450 Radical Aryl Migratases
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 1, 2025
Despite
its
synthetic
potential,
catalytic
enantioselective
Smiles
rearrangement
has
remained
elusive.
Through
the
directed
evolution
of
P450
radical
aryl
migratases
(P450Smiles's),
we
describe
first
example
rearrangement.
A
range
racemic
N-arylsulfonyl-α-chloroamides
could
be
transformed
by
P450Smiles
in
an
enantioconvergent
manner,
affording
acyclic
amide
products
possessing
all-carbon
quaternary
stereocenter
with
excellent
chemo-
and
enantioselectivity.
Both
electron-rich
electron-deficient
substituents
were
compatible
migrating
group,
demonstrating
this
P450-catalyzed
is
insensitive
to
electronic
properties
group.
Importantly,
our
evolved
variants
capable
overriding
innate
cyclization
activity
N-alkyl
amidyl
intermediate,
allowing
chemoselective
reductive
formation
products.
Classical
molecular
dynamics
(MD)
simulations
revealed
unusual
enzyme-controlled
chemoselectivity
stems
from
restricted
conformation
within
enzyme
active
site,
disfavoring
pathway.
This
new-to-nature
biocatalytic
asymmetric
showcases
potential
enzymatic
enantioselectivity
control
over
highly
reactive
intermediates
eluding
small-molecule
catalysts.
Язык: Английский