title: Biophysical evaluation of hybrid Fc fusion protein of hGH to achieve basal buffer system.
abstract: A newly developed hybrid Fc (hyFc) is a non-immunogenic and non-cytolytic Fc with intact Ig structure derived from human IgD and IgG4. It is fused with the human growth hormone (GXD-9) and was evaluated by various biophysical techniques. Two thermal transitions were evident by DSC, reflecting the unfolding of IgG4 and the conjugated protein. The highest Tmof the initial GXD-9 was 68.17°C and the Tmof the two domains were around 66°C and 70°C. Although Tmincreased with decreasing concentration, which reflects increasing conformational stability, aggregation issues were still observed by DLS. This might be caused by decreasing or low zeta potential due to a highly complex structure. The protein was dialyzed to various pH (6.2-8.2) values to enhance conformational stability and to overcome aggregation issues. The results of CD spectroscopy were correlated with DSC measurements to evaluate its conformational stability. Changes in secondary structural contents were similar as determined by DSC and DLS. In conclusion, GXD-9 was found to be most stable at pH 7.0. The investigation of the biophysical stability of a hyFc-fusion protein has demonstrated a positive feasibility of developing more stable formulations to facilitate the initial drug development process for further clinical trials.
authors.affiliation: College of Pharmacy, Dongguk University-Seoul, Gyeonggi 410-820, Republic of Korea.
authors.forename: Nam Ah
authors.initials: NA
authors.lastname: Kim
authors.affiliation: Research Institute, Genexine Inc., Seongnam, Gyeonggi 463-400, Republic of Korea.
authors.forename: In Bok
authors.initials: IB
authors.lastname: An
authors.affiliation: Research Institute, Genexine Inc., Seongnam, Gyeonggi 463-400, Republic of Korea.
authors.forename: Hye Seong
authors.initials: HS
authors.lastname: Lim
authors.affiliation: Research Institute, Genexine Inc., Seongnam, Gyeonggi 463-400, Republic of Korea.
authors.forename: Sang In
authors.initials: SI
authors.lastname: Yang
authors.affiliation: College of Pharmacy, Dongguk University-Seoul, Gyeonggi 410-820, Republic of Korea. Electronic address: shjeong@dongguk.edu.
authors.forename: Seong Hoon
authors.initials: SH
authors.lastname: Jeong
mesh_terms: D002021:Buffers; D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D004355:Drug Stability; D019382:Human Growth Hormone / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007141:Immunoglobulin Fc Fragments / Q000737:chemistry*; D007074:Immunoglobulin G / Q000737:chemistry*; D011487:Protein Conformation
chemical_list: D002021:Buffers; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D019382:Human Growth Hormone
keywords: CD spectroscopy; DSC; Fusion protein; Hybrid fc; hGH; pH