TY - JOUR
T1 - Kinetic analysis of the binding of monomeric and dimeric ephrins to Eph receptors
T2 - Correlation to function in a growth cone collapse assay
AU - Pabbisetty, Kumar B.
AU - Yue, Xin
AU - Li, Chen
AU - Himanen, Juha Pekka
AU - Zhou, Renping
AU - Nikolov, Dimitar B.
AU - Hu, Longqin
PY - 2007/3
Y1 - 2007/3
N2 - Eph receptors and ephrins play important roles in regulating cell migration and positioning during both normal and oncogenic tissue development. Using a surface plasma resonance (SPR) biosensor, we examined the binding kinetics of representative monomeric and dimeric ephrins to their corresponding Eph receptors and correlated the apparent binding affinity with their functional activity in a neuronal growth cone collapse assay. Our results indicate that the Eph receptor binding of dimeric ephrins, formed through fusion with disulfide-linked Fc fragments, is best described using a bivalent analyte model as a two-step process involving an initial monovalent 2:1 binding followed by a second bivalent 2:2 binding. The bivalent binding dramatically decreases the apparent dissociation rate constants with little effect on the initial association rate constants, resulting in a 30-to 6000-fold decrease in apparent equilibrium dissociation constants for the binding of dimeric ephrins to Eph receptors relative to their monomeric counterparts. Interestingly, the change was more prominent in the A-class ephrin/Eph interactions than in the B-class of ephrins to Eph receptors. The increase in apparent binding affinities correlated well with increased activation of Eph receptors and the resulting growth cone collapse. Our kinetic analysis and correlation of binding affinity with function helped us better understand the interactions between ephrins and Eph receptors and should be useful in the design of inhibitors that interfere with the interactions. Published by Cold Spring Harbor Laboratory Press.
AB - Eph receptors and ephrins play important roles in regulating cell migration and positioning during both normal and oncogenic tissue development. Using a surface plasma resonance (SPR) biosensor, we examined the binding kinetics of representative monomeric and dimeric ephrins to their corresponding Eph receptors and correlated the apparent binding affinity with their functional activity in a neuronal growth cone collapse assay. Our results indicate that the Eph receptor binding of dimeric ephrins, formed through fusion with disulfide-linked Fc fragments, is best described using a bivalent analyte model as a two-step process involving an initial monovalent 2:1 binding followed by a second bivalent 2:2 binding. The bivalent binding dramatically decreases the apparent dissociation rate constants with little effect on the initial association rate constants, resulting in a 30-to 6000-fold decrease in apparent equilibrium dissociation constants for the binding of dimeric ephrins to Eph receptors relative to their monomeric counterparts. Interestingly, the change was more prominent in the A-class ephrin/Eph interactions than in the B-class of ephrins to Eph receptors. The increase in apparent binding affinities correlated well with increased activation of Eph receptors and the resulting growth cone collapse. Our kinetic analysis and correlation of binding affinity with function helped us better understand the interactions between ephrins and Eph receptors and should be useful in the design of inhibitors that interfere with the interactions. Published by Cold Spring Harbor Laboratory Press.
KW - Eph receptor
KW - Ephrin
KW - Growth cone collapse
KW - Receptor dimerization
KW - Surface plasmon resonance
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U2 - https://doi.org/10.1110/ps.062608807
DO - https://doi.org/10.1110/ps.062608807
M3 - Article
C2 - 17322526
VL - 16
SP - 355
EP - 361
JO - Protein science : a publication of the Protein Society
JF - Protein science : a publication of the Protein Society
SN - 0961-8368
IS - 3
ER -