an investigation of the importance of the kinase hinge region on the structure and function of...
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An investigation of the importance of the Kinase Hinge region on the structure and function of selected Tyrosine Kinases
c-Kit :active in blue, inactive in yellow. Activation involves a 6.7 degree tilt on the N-lobe towards the C-lobe
N-lobe
C-lobe
c-Kit : key structural components
Active form of c-Kit : juxtamembrane :green; P loop :magenta; C (control) –helix :cyan ; C (catalytic) loop :gray ; A (activation) loop: red
-C Glu is “in”
DFG Phe is “in”
Inactive form of c-Kit : juxtamembrane :green; P loop :magenta; C (control) –helix :cyan ; C (catalytic) loop :gray ; A (activation) loop: red
-C Glu is “in”
DFG Phe is “out”
Inactive form of c-Kit + Gleevec : juxtamembrane :green; P loop :magenta; C (control) –helix :cyan ; C (catalytic) loop :gray ; A (activation) loop: red
Active form of c-Kit: blue ; Inactive form : yellowThe molecular brake and the kinase hinge
Induced fit of STI binding to c-Kit : 1T45 in yellow, 1T46 in gray
Inactive of c-Kit formThe molecular brake and the kinase hinge
Active form of c-KitThe molecular brake and the kinase hinge
Inactive c-Kit + STI (1T46)
STI induces fit in molecular breakVan der Waals surface detailing the binding pocket for
1T46 + STI ; Red : Ile 653
STI induces fit in molecular break
Solvent accessible surface forInactive c-Kit + STI (1T46)
Solvent accessible surface forModified c-Kit (1T46+ brake on +STI)
Mechanism for release of the molecular brake through movement of Activation loop involves a similar
interaction between Ile653 and Phe 811
fesfer FES
matkcsk
frkfgr
fynyes
srcblklynhck
lcksrms
ptk6btk
bmxitk
tectxk
abl2abl1 epha8
ephb4ephb3ephb2
ephb1epha7epha6epha4epha5
epha3epha2epha1
ephazap-70
sykfak2
fak1tnk1
ack1 jak3jak2tyk2
jak1erbb3
erbb4erbb2
erbb1itk
alkros1
insrrigf1r
insr aatykaatk
ptk7ddr2ddr1ror2ror1
muskntrk3
ntrk2ntrk1
rykron
mettyro3
axlmertk
tektie
retfgfr4fgfr3
fgfr2fgfr1 vegfr3
vegfr2vegfr1pdgfrb
pdgfraflt3csf1r
ckit
CSK
SRC
BRK
TEC
ABL
EPH
SYKFAK
ACK
JAK
EGFR
ALKROSINSR
AATYKPTK7DDRRORMUSKTRKRYKMET
UFO
TIERET
FGFR
VEGFR
PDGFR
**K
NEK
*EK
***
Phylogenetic Tree of Human Tyrosine Kinases
fgfr2 481c-Kit 589abl1 242
fgfr2 541c-Kit 647abl1 293
fgfr2 582c-Kit 707abl1 335
fgfr2 601c-Kit 767abl1 338
fgfr2 661c-Kit 827abl1 397
fgfr2 720c-Kit 887abl1 456
541646292
581706334
600766337
660826396
719886455
770937493
1 2 3 -C helix
4 5 6 -D
-E 7 8
-F -G -H -I
-J -K -L
The effect of Ligand binding on the “Molecular Brake” of the Kinase Hinge region of Tyrosine Kinases
No such interaction is present in abl since no h-bond stabilization is needed; molecular brake is off for
hinge region of Inactive abl + STI (1OPJ)
Leu 317 in abl compared to Ile 653 in c-Kit
Gln 319 in abl compared to Asn 655 in c-Kit
Result#4: Inhibition of c-Kit through the binding of ellipticines
Inhibition of abl through the binding of ellipticines
Inhibition of c-Kit through the binding of ellipticines : competitive inhibition
HO-ellipticine: Blue
MeO-ellipticene: green
ADP: Cyan
Inhibition of c-Kit through the binding of ellipticines ; OMe-Phe401 hydrophobic
interaction stabilizing backbone h-bond
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