title: Histone-dependent IgG conservation in octanoic acid precipitation and its mechanism.
abstract: Octanoic acid (OA) precipitation has long been used in protein purification. Recently, we reported a new cell culture clarification method for immunoglobulin G (IgG) purification, employing an advance elimination of chromatin heteroaggregates with a hybrid OA-solid phase system. This treatment reduced DNA more than 3 logs, histone below the detection limit (LOD), and non-histone host cell proteins (nh-HCP) by 90 % while conserving more than 90 % of the IgG monomer. In this study, we further investigated the conservation of IgG monomer and antibody light chain (LC) to the addition of OA/OA-solid phase complex, with or without histone and DNA in different combinations. The results showed that highly basic histone protein was the prime target in OA/OA-solid phase precipitation system for IgG purification, and the selective conservation of IgG monomer in this system was histone dependent. Our findings partially support the idea that OA works by sticking to electropositive hydrophobic domains on proteins, reducing their solubility, and causing them to agglomerate into large particles that precipitate from solution. Our findings also provide a new perspective for IgG purification and emphasize the necessity to re-examine the roles of various host contaminants in IgG purification.
authors.affiliation: CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
authors.forename: Phyllicia
authors.initials: P
authors.lastname: Toh
authors.affiliation: CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
authors.forename: Sarah Maria Abdul
authors.initials: SM
authors.lastname: Latiff
authors.affiliation: Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
authors.forename: Aina
authors.initials: A
authors.lastname: Hoi
authors.affiliation: CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Mo
authors.initials: M
authors.lastname: Xian
authors.affiliation: CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Haibo
authors.initials: H
authors.lastname: Zhang
authors.affiliation: CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China. nianrui@qibebt.ac.cn.
authors.forename: Rui
authors.initials: R
authors.lastname: Nian
authors.affiliation: Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore. zhang_wei@bti.a-star.edu.sg.
authors.forename: Wei
authors.identifier: http://orcid.org/0000-0001-8597-5357
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
authors.forename: Pete
authors.initials: P
authors.lastname: Gagnon
mesh_terms: D002210:Caprylates / Q000378:metabolism*; D011232:Chemical Precipitation; D002845:Chromatography; D006570:Heterochromatin / Q000302:isolation & purification; D006657:Histones / Q000302:isolation & purification; D007074:Immunoglobulin G / Q000302:isolation & purification*; D007155:Immunologic Factors / Q000302:isolation & purification*; D011994:Recombinant Proteins / Q000302:isolation & purification
chemical_list: D002210:Caprylates; D006570:Heterochromatin; D006657:Histones; D007074:Immunoglobulin G; D007155:Immunologic Factors; D011994:Recombinant Proteins; C031492:octanoic acid
keywords: Agglomeration; Histone; IgG; Light chain; Octanoic acid