The Versatility of Framework Regions of Chicken VH and VL to Mutations

Jung Won Shin; Sang Il Kim; Aerin Yoon; Junyeong Jin; Hyung Bae Park; Hyori Kim; Junho Chung

doi:10.4110/in.2018.18.e3

The Versatility of Framework Regions of Chicken V_H and V_L to Mutations

Immune Netw. 2018 Jan 31;18(2):e3. doi: 10.4110/in.2018.18.e3. eCollection 2018 Apr.

Authors

Jung Won Shin^{1

2}, Sang Il Kim^{2

3}, Aerin Yoon^{1

2}, Junyeong Jin^{1

2}, Hyung Bae Park^{1

4}, Hyori Kim⁵, Junho Chung^{1

2}

Affiliations

¹ Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea.
² Cancer Research Institute, Seoul National University College of Medicine, Seoul 03080, Korea.
³ Department of Cancer Biology, Seoul National University College of Medicine, Seoul 03080, Korea.
⁴ Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea.
⁵ Biomedical Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea.

Abstract

To identify the interchangeability of V_H and V_L framework region (FR) residues, we artificially introduced random mutations at all residue positions in a chicken monoclonal antibody, which has only one functional V_H and V_λ gene. When we classified the amino acids into 5 groups by their physicochemical properties, all FR residues could be replaced by another group except L23 (C), H36 (W), H86 (D), H104 (G), and H106 (G). Eighty-two (50.9%), 48 (29.8%), 17 (10.6%), and 9 FR residues (5.6%) could be replaced by 4, 3, 2, and 1 group(s), individually, without significant loss of reactivity. We also confirmed a similar level of versatility with 2 different chicken antibodies. This high level of versatility on FR residues has not been predicted because it has not been observed in the 150 chicken antibodies that we previously generated or in the 1,269 naïve chicken V_H sequences publically available. In conclusion, chicken antibody FR residues are highly interchangeable and this property can be applied for improving the physicochemical property of antibody including thermal stability, solubility and viscosity.

Keywords: Chicken; Ig Framework region; Immunoglobulin somatic hypermutation; Mutation.