title: Generation and characterization of a single-chain anti-EphA2 antibody.
abstract: Recombinant antibody phage library technology provides multiple advantages, including that human antibodies can be generated against proteins that are highly conserved between species. We used this technology to isolate and characterize an anti-EphA2 single-chain antibody. We show that the antibody binds the antigen with 1:1 stoichiometry and has high specificity for EphA2. The crystal structure of the complex reveals that the antibody targets the same receptor surface cavity as the ephrin ligand. Specifically, a lengthy CDR-H3 loop protrudes deep into the ligand-binding cavity, with several hydrophobic residues at its tip forming an anchor-like structure buried within the hydrophobic Eph pocket, in a way similar to the ephrin receptor-binding loop in the Eph/ephrin structures. Consequently, the antibody blocks ephrin binding to EphA2. Furthermore, it induces apoptosis and reduces cell proliferation in lymphoma cells lines. Since Ephs are important mediators of tumorigenesis, such antibodies could have applications both in research and therapy.
authors.affiliation: Structural Biology Program, Memorial Sloan-Kettering Cancer Center , New York, NY , USA .
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Goldgur
authors.forename: Petri
authors.initials: P
authors.lastname: Susi
authors.forename: Eveliina
authors.initials: E
authors.lastname: Karelehto
authors.forename: Hanna
authors.initials: H
authors.lastname: Sanmark
authors.forename: Urpo
authors.initials: U
authors.lastname: Lamminmäki
authors.forename: Elisa
authors.initials: E
authors.lastname: Oricchio
authors.forename: Hans-Guido
authors.initials: HG
authors.lastname: Wendel
authors.forename: Dimitar B
authors.initials: DB
authors.lastname: Nikolov
authors.forename: Juha P
authors.initials: JP
authors.lastname: Himanen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000915:Antibody Affinity; D001666:Binding Sites, Antibody; D019556:COS Cells; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D057809:HEK293 Cells; D006801:Humans; D008969:Molecular Sequence Data; D036104:Receptor, EphA2 / Q000276:immunology*; D057127:Single-Chain Antibodies / Q000737:chemistry / Q000276:immunology*
chemical_list: D057127:Single-Chain Antibodies; D036104:Receptor, EphA2
keywords: Crystal structure; eph receptor; single-chain antibody