title: [Effect of affinity medium and solution conditions on endotoxin removal from protein solutions].
abstract: Endotoxin removal is essential for the safety of biological products. To remove endotoxin efficiently, we used polymyxin B (PMB) affinity adsorbent to remove endotoxin from protein solutions by static adsorption. We studied the effects of spacer length and ligand density of the affinity adsorbent, pH, salt type and concentration, protein type and concentration, endotoxin concentration, and additive on endotoxin removal and protein recovery. Endotoxin content and protein concentration were determined by test and Lowry assay respectively. The results showed that PMB affinity adsorbent had high capacity, high adsorption speed, high removal efficiency and good reusability. In addition, ligand density, pH, salt concentration and the isoelectric point and hydrophobicity of protein all had remarkable influence on the endotoxin removal. Under the optimal conditions, the recoveries of hemoglobin, human serum albumin and lysozyme were 87.2%, 73.4% and 97.3%, respectively, and the corresponding endotoxin removal rates 99.8%, 97.9% and 99.7%, respectively. This study illustrated the effects of solution conditions on the efficiency of endotoxin removal and protein recovery, and would provide useful reference for the efficient removal of endotoxin from biological products.
authors.affiliation: College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Haixin
authors.initials: H
authors.lastname: Xing
authors.forename: Yongdong
authors.initials: Y
authors.lastname: Huang
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Jian
authors.initials: J
authors.lastname: Luo
authors.forename: Liye
authors.initials: L
authors.lastname: Zhang
authors.forename: Guanghui
authors.initials: G
authors.lastname: Ma
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Su
mesh_terms: D000327:Adsorption; D002846:Chromatography, Affinity / Q000379:methods; D004340:Drug Contamination / Q000517:prevention & control*; D004731:Endotoxins / Q000302:isolation & purification*; D006454:Hemoglobins / Q000302:isolation & purification; D011112:Polymyxin B / Q000737:chemistry*; D011506:Proteins / Q000302:isolation & purification*; D011749:Pyrogens / Q000302:isolation & purification; D012709:Serum Albumin / Q000302:isolation & purification; D012996:Solutions
chemical_list: D004731:Endotoxins; D006454:Hemoglobins; D011506:Proteins; D011749:Pyrogens; D012709:Serum Albumin; D012996:Solutions; D011112:Polymyxin B