Chemistry Reference
In-Depth Information
lo
re
fr
ow binding a
esponse of th
ree states [4]
affinity and
he ligand nu
].
high dissoci
uclei and the
iation consta
protein is an
ant, K
D
> µM
n average be
M) the observ
etween the b
ved NMR
bound and
(3)
A
eq
bo
in
w
bo
According to
quilibrium s
ound ligand,
n its free and
where X
R
and
ound and oc
o Equation
system, X
L
(f
, and M
L
(fre
d bound state
d M
R
are now
ccupied recep
3, M
obs
is
free) and X
L
ee) and M
L
(b
es, respectiv
w the mole f
ptor. The mo
s any NMR
L
(bound) ar
bound) are t
vely. Likewis
fraction and
ole fractions
R observabl
re the mole
the NMR par
se for observ
d the NMR p
s are defined
le paramete
fractions of
rameters of t
vation of the
parameters o
d by Equation
er of the
f free and
the ligand
e receptor,
f the non-
n 4 [2].
(4)
W
m
re
ch
re
po
re
in
When the exc
magnitude of
esonances ca
haracteristic
elative to the
osition is the
elative popul
n line shape, w
change is ve
f the chemic
an be seen
of the two st
e chemical sh
e average of
ations (Equa
which are ve
ery slow on
al shift diffe
at the pos
tates. At the
hift differenc
f the chemic
ation 3). Betw
ry sensitive t
n the “NMR
erence betwe
sitions corre
other extrem
ce, a single r
cal shifts of
ween these ex
to the precise
R timescale”
een the two
esponding to
me, when the
resonance wi
the two stat
xtremes there
e value of the
- here relati
states - two
o the chemi
e exchange is
ill be observ
tes, weighted
e are comple
e rate exchang
ive to the
o separate
ical shifts
s very fast
ved, whose
d by their
ex changes
ge [4].
N
NMR-Based
Methods in
n Protein-Li
igand Bindi
ing Affinity
N
m
pr
m
N
ob
ta
in
NMR spectro
molecular str
rovide infor
methodology
NMR chemic
btain inform
arget, and wh
nteraction [1
oscopy is hig
ructures, but
rmation abo
is known a
cal shift, is h
mation about
hat parts of t
0].
ghly used as
t in drug dis
ut intermole
s NMR scre
highly sensit
t how a sm
the small mo
s a powerful
scovery its g
ecular intera
eening. Once
tive to envir
mall molecule
olecule or wh
l technique t
greatest pot
actions at th
e a simple p
ronment of t
e is bound
hich fragmen
to view full
ential is its
he atomic le
parameter, su
the atom, al
to a macrom
nts are respo
details of
ability to
evel. This
uch as the
llowing to
molecular
onsible by
S
m
tockman an
molecules lig
nd Dalvit d
gands for m
defined NMR
acromolecul
R screening
lar targets b
g as the id
by observatio
dentification
on of a cha
of small
nge in an
