title: Purification of apolipoprotein H by polyethylene glycol precipitation.
abstract: A new method of polyethylene glycol precipitation followed by heparin affinity chromatography was established to purify apolioprotein H (Apo H, beta 2-glycoprotein I). This method is simple and effective and yields more harvest of Apo H (3-4 mg Apo H from 100 ml fetal bovine serum) than the current HClO4 extraction method. There are notable differences between Apo H purified by the polyethylene glycol method [Apo H (PEG)] and Apo H purified by the HClO4 method [Apo H (HClO4)] in respects of their SDS electrophoresis characteristics, circular dichroism spectroscopy, and isoelectric focusing graph. It is concluded that the strong acid HClO4 treatment may induce some disordered structure in Apo H molecule resulting in the lowering of molecular weight and pIs. Apo H (PEG) retains more integrated structure which may be related to its bioactivity.
authors.affiliation: Department of Biological Science & Biotechnology, Tsinghua University, Beijing, China.
authors.forename: G
authors.initials: G
authors.lastname: Cai
authors.forename: Y
authors.initials: Y
authors.lastname: Guo
authors.forename: J
authors.initials: J
authors.lastname: Shi
mesh_terms: D001053:Apolipoproteins / Q000737:chemistry / Q000302:isolation & purification*; D011232:Chemical Precipitation; D002846:Chromatography, Affinity; D002942:Circular Dichroism; D006023:Glycoproteins / Q000737:chemistry / Q000302:isolation & purification*; D007525:Isoelectric Focusing; D008970:Molecular Weight; D010472:Perchlorates; D011092:Polyethylene Glycols; D053482:beta 2-Glycoprotein I
chemical_list: D001053:Apolipoproteins; D006023:Glycoproteins; D010472:Perchlorates; D053482:beta 2-Glycoprotein I; D011092:Polyethylene Glycols