title: Comprehensive Characterization of Relationship Between Higher-Order Structure and FcRn Binding Affinity of Stress-Exposed Monoclonal Antibodies.
abstract: OBJECTIVE
  In biopharmaceutical development, information regarding higher-order structure (HOS) is important to verify quality and characterize protein derivatives. In this study, we aimed to characterize the association between HOS and pharmacokinetic property of a stress-exposed monoclonal antibody (mAb).
  
  
  METHODS
  Purity, primary structure, thermal stability, and HOS were evaluated for mAbs exposed to heat, photo-irradiation, and chemical oxidation. To investigate conformation of stress-exposed mAbs, hydrogen/deuterium exchange coupled with mass spectrometry (HDX-MS) was utilized.
  
  
  RESULTS
  No distinct difference in secondary or tertiary structure between stress-exposed and non-stressed samples was found by conventional spectroscopic techniques. In binding activity with the neonatal Fc receptor (FcRn), however, a marked decline was observed for force-oxidized mAb and a slight decline was observed for heat- and photodegraded mAbs. Using differential scanning calorimetry, a change in thermal stability was observed in the CH2 domain for all the stress-exposed samples. Using HDX-MS analyses, individual regions with altered conformation could be identified for heat-degraded and force-oxidized samples.
  
  
  CONCLUSIONS
  These findings indicate that comprehensive study is important for detecting conformational changes and helpful for predicting biophysical property, and that the evaluation of HOS using several analytical techniques is indispensable for confirming biopharmaceutical quality.
authors.affiliation: Bio Process Research and Development Laboratories, Kyowa Hakko Kirin Co., Ltd., 100-1 Hagiwara-machi, Takasaki, Gunma, 370-0013, Japan. daisuke.tsuchida@kyowa-kirin.co.jp.|Graduated School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan. daisuke.tsuchida@kyowa-kirin.co.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tsuchida
authors.affiliation: Bio Process Research and Development Laboratories, Kyowa Hakko Kirin Co., Ltd., 100-1 Hagiwara-machi, Takasaki, Gunma, 370-0013, Japan.
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Yamazaki
authors.affiliation: Graduated School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan. akashi@tsurumi.yokohama-cu.ac.jp.
authors.forename: Satoko
authors.initials: S
authors.lastname: Akashi
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006358:Hot Temperature; D007074:Immunoglobulin G / Q000737:chemistry / Q000276:immunology; D010084:Oxidation-Reduction; D010782:Photolysis; D011487:Protein Conformation; D055550:Protein Stability; D011961:Receptors, Fc / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D015395:Histocompatibility Antigens Class I; D007074:Immunoglobulin G; D011961:Receptors, Fc; C100688:Fc receptor, neonatal
keywords: FcRn; HDX–MS; higher-order structure; monoclonal antibody