title: Purification of α2-macroglobulin from Cohn Fraction IV by immobilized metal affinity chromatography: A promising method for the better utilization of plasma.
abstract: As an abundant plasma protein, α2-macroglobulin (α2-M) participates widely in physiological and pathological activities including coagulation regulation, antitumor activities, and regulation of cytokines. It also presents a therapeutic potential for radiation injury. A two-step isolation method for the purification of α2-M from Cohn Fraction IV is described. This process includes a salting-out method and immobilized metal affinity chromatography. The LC-ESI-MS/MS analysis and a comparison of the amino acid composition demonstrated that the final product was α2-M. The final protein, with a purity of approximately 95% and a yield of nearly 45%, was obtained from Cohn Fraction IV regardless of plasma haptoglobin type, although all but type 1-1 have previously been considered unfavorable for α2-M preparation. The effects of temperature, pH, and methylamine on α2-M activity were evaluated to avoid activity loss during preparation and preservation. The results suggested that α2-M activity could be readily inactivated at temperatures above 50°C, at pH levels above 9.0 or below 4.0, or in the presence of methylamine. Cohn Fraction IV is usually discarded as a biological waste product in the human serum albumin production process; because the simple process developed in this study is relatively inexpensive, the preparation of α2-M from Cohn Fraction IV may better utilize human plasma, a valuable resource.
authors.affiliation: Beijing key Laboratory of Blood Safety and Supply Technologies & Blood Products and Substitute Laboratory, Beijing Institute of Transfusion Medicine, No 27 Taiping Road, Haidian District, Beijing 100850, China. Electronic address: Huangfuhfcj0817@sina.com.
authors.forename: Chaoji
authors.initials: C
authors.lastname: Huangfu
authors.affiliation: Beijing key Laboratory of Blood Safety and Supply Technologies & Blood Products and Substitute Laboratory, Beijing Institute of Transfusion Medicine, No 27 Taiping Road, Haidian District, Beijing 100850, China. Electronic address: mayuyuan07@hotmail.com.
authors.forename: Yuyuan
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Beijing key Laboratory of Blood Safety and Supply Technologies & Blood Products and Substitute Laboratory, Beijing Institute of Transfusion Medicine, No 27 Taiping Road, Haidian District, Beijing 100850, China. Electronic address: 13641321817@126.com.
authors.forename: Maomin
authors.initials: M
authors.lastname: Lv
authors.affiliation: Beijing key Laboratory of Blood Safety and Supply Technologies & Blood Products and Substitute Laboratory, Beijing Institute of Transfusion Medicine, No 27 Taiping Road, Haidian District, Beijing 100850, China. Electronic address: junting1006@163.com.
authors.forename: Junting
authors.initials: J
authors.lastname: Jia
authors.affiliation: Beijing key Laboratory of Blood Safety and Supply Technologies & Blood Products and Substitute Laboratory, Beijing Institute of Transfusion Medicine, No 27 Taiping Road, Haidian District, Beijing 100850, China. Electronic address: zhaoxiong1980@126.com.
authors.forename: Xiong
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Beijing key Laboratory of Blood Safety and Supply Technologies & Blood Products and Substitute Laboratory, Beijing Institute of Transfusion Medicine, No 27 Taiping Road, Haidian District, Beijing 100850, China. Electronic address: zhangjg@bmi.ac.cn.
authors.forename: Jingang
authors.initials: J
authors.lastname: Zhang
mesh_terms: D001798:Blood Proteins / Q000737:chemistry*; D002846:Chromatography, Affinity / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008744:Methylamines; D053719:Tandem Mass Spectrometry; D013696:Temperature; D000511:alpha-Macroglobulins / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D001798:Blood Proteins; C032309:Cohn fraction IV; D008744:Methylamines; D000511:alpha-Macroglobulins; C027451:methylamine
keywords: Better utilization of plasma; Cohn fraction IV; Immobilized metal affinity chromatography; Plasma derivatives; α2-macroglobulin