Structural analysis of chick ephrin-A2 by function-blocking and non-blocking monoclonal antibodies.
Ephrins, ligands for the Eph family of receptor tyrosine kinases, play key roles in diverse biological processes. In this study, we determined the epitopes and kinetic parameters of function-blocking (B3) and non-blocking (IV) monoclonal antibodies (mAbs) recognizing chick ephrin-A2. We show that the epitope for the non-blocking mAb is the residue Asp(105) of chick ephrin-A2. However, the binding of the function-blocking mAb depends mostly on residue Ser(108) and its epitope may reside within residues 105-132, which appear crucial for the receptor interaction site. Kinetic studies suggest a possible mechanism why mAb IV, despite recognizing a region very close to the mAb B3 epitope, fails to block the ligand-receptor interaction.
Ahsan
Mansoor
M
Division of Developmental Neurobiology, Kumamoto University Graduate School of Medical Sciences, Honjo 2, Kumamoto 860-0811, Japan.
Yin
Yanzhi
Y
Ueno
Takamasa
T
Takiguchi
Masafumi
M
Tanaka
Hideaki
H
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001483:Base Sequence; D002460:Cell Line; D002645:Chickens; D017931:DNA Primers; D036383:Ephrin-A2; D006801:Humans; D007700:Kinetics; D008024:Ligands; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000276:immunology; D020349:Surface Plasmon Resonance; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000737:chemistry*
D000911:Antibodies, Monoclonal; D017931:DNA Primers; D036383:Ephrin-A2; D008024:Ligands; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors