Journal of the American Chemical Society,
Journal Year:
2021,
Volume and Issue:
143(2), P. 1107 - 1118
Published: Jan. 7, 2021
Artificial
enzymatic
systems
are
extensively
studied
to
mimic
the
structures
and
functions
of
their
natural
counterparts.
However,
there
remains
a
significant
gap
between
structural
modeling
catalytic
activity
in
these
artificial
systems.
Herein
we
report
novel
strategy
for
construction
an
binuclear
copper
monooxygenase
starting
from
Ti
metal–organic
framework
(MOF).
The
deprotonation
hydroxide
groups
on
secondary
building
units
(SBUs)
MIL-125(Ti)
(MIL
=
Matériaux
de
l'Institut
Lavoisier)
allows
metalation
SBUs
with
closely
spaced
CuI
pairs,
which
oxidized
by
molecular
O2
afford
CuII2(μ2-OH)2
cofactor
MOF-based
Ti8-Cu2.
An
mononuclear
Cu
Ti8-Cu1
was
also
prepared
comparison.
monooxygenases
were
characterized
combination
thermogravimetric
analysis,
inductively
coupled
plasma–mass
spectrometry,
X-ray
absorption
spectroscopy,
Fourier-transform
infrared
UV–vis
spectroscopy.
In
presence
coreductants,
Ti8-Cu2
exhibited
outstanding
toward
wide
range
monooxygenation
processes,
including
epoxidation,
hydroxylation,
Baeyer–Villiger
oxidation,
sulfoxidation,
turnover
numbers
up
3450.
showed
frequency
at
least
17
times
higher
than
that
Ti8-Cu1.
Density
functional
theory
calculations
revealed
activation
as
rate-limiting
step
processes.
Computational
studies
further
Cu2
sites
cooperatively
stabilized
Cu–O2
adduct
O–O
bond
cleavage
6.6
kcal/mol
smaller
free
energy
increase
Ti8-Cu1,
accounting
significantly
over
Protein Science,
Journal Year:
2015,
Volume and Issue:
24(9), P. 1360 - 1369
Published: June 24, 2015
Abstract
Tyrosinases
are
metalloenzymes
belonging
to
the
type‐3
copper
protein
family
which
contain
two
ions
in
active
site.
They
found
various
prokaryotes
as
well
plants,
fungi,
arthropods,
and
mammals
responsible
for
pigmentation,
wound
healing,
radiation
protection,
primary
immune
response.
perform
sequential
enzymatic
reactions:
hydroxylation
of
monophenols
oxidation
diphenols
form
quinones
polymerize
spontaneously
melanin.
Two
other
members
this
catechol
oxidases,
prevalent
mainly
plants
only
second
step,
hemocyanins,
lack
activity
oxygen
carriers.
In
last
decade,
several
structures
plant
bacterial
tyrosinases
were
determined,
some
with
substrates
or
inhibitors,
highlighting
features
residues
important
uptake
catalysis.
This
review
summarizes
updated
information
on
structure–function
correlations
along
comparison
proteins.
Cosmetics,
Journal Year:
2019,
Volume and Issue:
6(4), P. 57 - 57
Published: Oct. 1, 2019
One
of
the
most
common
approaches
for
control
skin
pigmentation
involves
inhibition
tyrosinase,
a
copper-containing
enzyme
which
catalyzes
key
steps
melanogenesis.
This
review
focuses
on
tyrosinase
properties
series
natural
and
synthetic,
bioinspired
phenolic
compounds
that
have
appeared
in
literature
last
five
years.
Both
mushroom
human
inhibitors
been
considered.
Among
first
class,
flavonoids,
particular
chalcones,
occupy
prominent
role
as
inhibitors,
followed
by
hydroxystilbenes
(mainly
resveratrol
derivatives).
A
more
complex
from
variety
sources,
all
belonging
to
Moraceae
family,
also
described
potent
inhibitors.
As
synthetic
compounds,
hydroxycinnamic
acids
chalcones
again
appear
exploited
scaffolds.
Several
mechanisms
reported
pointing
copper
chelating
and/or
hydrophobic
moieties
structural
requirements
achieve
good
properties.
Emerging
trends
search
novel
depigmenting
agents,
including
development
assays
could
distinguish
between
potentially
toxic
substrates
well
formulations
aimed
at
improving
bioavailability
hence
effectiveness
well-known
addressed.
RSC Advances,
Journal Year:
2021,
Volume and Issue:
11(36), P. 22159 - 22198
Published: Jan. 1, 2021
This
review
revealed
that
among
all
the
natural
and
synthetic
flavonoids,
inhibitory
findings
suggest
flavonol
moiety
can
serve
as
an
effective
a
lead
structural
scaffold
for
further
development
of
novel
TIs.
Scientific Reports,
Journal Year:
2016,
Volume and Issue:
6(1)
Published: Oct. 11, 2016
Abstract
Tyrosinases
are
responsible
for
melanin
formation
in
all
life
domains.
Tyrosinase
inhibitors
used
the
prevention
of
severe
skin
diseases,
skin-whitening
creams
and
to
avoid
fruit
browning,
however
continued
use
many
such
is
considered
unsafe.
In
this
study
we
provide
conclusive
evidence
inhibition
mechanism
two
well
studied
tyrosinase
inhibitors,
KA
(kojic
acid)
HQ
(hydroquinone),
which
extensively
hyperpigmentation
treatment.
reported
literature
with
contradicting
mechanisms,
while
described
as
both
a
inhibitor
substrate.
By
visualization
active
site
TyrBm
crystals,
together
molecular
modeling,
binding
constant
analysis
kinetic
experiments,
have
elucidated
their
mechanisms
inhibition,
was
ambiguous
inhibitors.
We
confirm
that
acts
mixed
inhibitor,
can
act
substrate
an
inhibitor.
Molecules,
Journal Year:
2019,
Volume and Issue:
24(11), P. 2064 - 2064
Published: May 30, 2019
Natural
water
sources
are
very
often
contaminated
by
municipal
wastewater
discharges
which
contain
either
of
xenobiotic
pollutants
and
their
sometimes
more
toxic
degradation
products,
or
both,
frustrates
the
universal
millenium
development
goal
provision
relatively
scarce
pristine
freshwater
to
water-scarce
-stressed
communities,
in
order
augment
socioeconomic
well-being.
Seeing
that
both
regulatory
measures,
as
regards
discharge
limits
wastewater,
query
for
efficient
treatment
methods
remain
unanswered,
partially,
prospects
enzymatic
is
advisable.
Therefore,
a
reconsideration
was
assigned
possible
capacity
oxidative
enzymes
respective
challenges
encountered
during
applications
treatment,
ultimately,
laccase,
polyphenol
oxidase
oxidizes
aromatic
inorganic
substrates
with
electron-donating
groups
contaminants
real
situations,
since
it
assumed
be
vehicle
greener
community.
Furthermore,
importance
laccase-driven
catalysis
toward
maintaining
mass-energy
balance,
hence
minimizing
environmental
waste,
comprehensibly
elucidated,
well
strategic
positioning
laccase
model
facility
effective
contaminants.
Acta Crystallographica Section D Biological Crystallography,
Journal Year:
2014,
Volume and Issue:
70(9), P. 2301 - 2315
Published: Aug. 29, 2014
Tyrosinases,
bifunctional
metalloenzymes,
catalyze
the
oxidation
of
monophenols
and
o-diphenols
to
o-quinones,
precursor
compounds
brown-coloured
pigment
melanin.
In
eukaryotic
organisms,
tyrosinases
are
expressed
as
latent
zymogens
that
have
be
proteolytically
cleaved
in
order
form
highly
active
enzymes.
This
activation
mechanism,
known
tyrosinase
maturation
process,
has
scientific
industrial
significance
with
respect
biochemical
technical
applications
enzyme.
Here,
not
only
first
crystal
structure
mushroom
abPPO4
is
presented
its
(Ser2-Ser383)
21
kDa
heavier
(Ser2-Thr545),
but
furthermore
simultaneous
presence
both
forms
within
one
single-crystal
shown.
allows
for
a
simple
approach
investigate
transition
between
these
two
forms.
Isoform
was
isolated
extensively
purified
from
natural
source
(Agaricus
bisporus),
which
contains
total
six
polyphenol
oxidases
(PPOs).
The
enzyme
formed
crystals
(diffracting
resolution
2.76
Å)
owing
employment
6-tungstotellurate(VI)
salt
(Na6[TeW6O24]·22H2O)
cocrystallization
agent.
Two
disc-shaped
Anderson-type
polyoxoanions
[TeW6O24](6-)
separate
asymmetric
units
comprising
crystallographic
heterodimer
abPPO4,
thus
resulting
very
interesting
packing.
