title: TRAIL-R2 Superoligomerization Induced by Human Monoclonal Agonistic Antibody KMTR2.
abstract: The fully human monoclonal antibody KMTR2 acts as a strong direct agonist for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor 2 (TRAIL-R2), which is capable of inducing apoptotic cell death without cross-linking. To investigate the mechanism of direct agonistic activity induced by KMTR2, the crystal structure of the extracellular region of TRAIL-R2 and a Fab fragment derived from KMTR2 (KMTR2-Fab) was determined to 2.1 Å resolution. Two KMTR2-Fabs assembled with the complementarity-determining region 2 of the light chain via two-fold crystallographic symmetry, suggesting that the KMTR2-Fab assembly tended to enhance TRAIL-R2 oligomerization. A single mutation at Asn53 to Arg located at the two-fold interface in the KMTR2 resulted in a loss of its apoptotic activity, although it retained its antigen-binding activity. These results indicate that the strong agonistic activity, such as apoptotic signaling and tumor regression, induced by KMTR2 is attributed to TRAIL-R2 superoligomerization induced by the interdimerization of KMTR2.
authors.affiliation: Quantum Beam Science Center, Japan Atomic Energy Agency, 2-4, Shirakata, Tokai, Ibaraki 319-1195, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Tamada
authors.affiliation: Research Core Function Laboratories, R&D Division, Kyowa Hakko Kirin Co., Ltd., 3-6-6, Asahi-machi, Machida, Tokyo, 194-8533, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Shinmi
authors.affiliation: Immunology &Allergy Research Laboratories, R&D Division, Kyowa Hakko Kirin Co., Ltd., 3-6-6, Asahi-machi, Machida, Tokyo, 194-8533, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ikeda
authors.affiliation: Quantum Beam Science Center, Japan Atomic Energy Agency, 2-4, Shirakata, Tokai, Ibaraki 319-1195, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yonezawa
authors.affiliation: Business Development Department, Kyowa Hakko Kirin Co., Ltd., 1-6-1, Ohtemachi, Chiyoda-ku, Tokyo, 100-8185, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Kataoka
authors.affiliation: Quantum Beam Science Center, Japan Atomic Energy Agency, 2-4, Shirakata, Tokai, Ibaraki 319-1195, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Kuroki
authors.affiliation: R&D Planning Department, R&D Division, Kyowa Hakko Kirin Co., Ltd., 1-6-1, Ohtemachi, Chiyoda-ku, Tokyo, 100-8185, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Mori
authors.affiliation: Oncology Research Laboratories, R&D Division, Kyowa Hakko Kirin Co., Ltd., 3-6-6, Asahi-machi, Machida, Tokyo, 194-8533, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Motoki
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001665:Binding Sites / Q000235:genetics; D016466:CHO Cells; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D006224:Cricetinae; D003412:Cricetulus; D018360:Crystallography, X-Ray; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D008958:Models, Molecular; D046912:Multiprotein Complexes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020125:Mutation, Missense; D011485:Protein Binding; D055503:Protein Multimerization / Q000187:drug effects*; D017434:Protein Structure, Tertiary; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000819:agonists* / Q000737:chemistry* / Q000235:genetics; D013237:Stereoisomerism
chemical_list: D000911:Antibodies, Monoclonal; D007140:Immunoglobulin Fab Fragments; D046912:Multiprotein Complexes; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand