title: Effect of IDA and TREN chelating agents and buffer systems on the purification of human IgG with immobilized nickel affinity membranes.
abstract: The purification of IgG from human plasma was studied by comparing two affinity membranes complexed with Ni(II), prepared by coupling iminodiacetic acid (IDA) and Tris(2-aminoethyl)amine (TREN) to poly(ethylenevinyl alcohol), PEVA, hollow fiber membranes. The Ni(II)-TREN-PEVA hollow fiber membrane had lower capacity for human IgG than the complex Ni(II)-IDA-PEVA, but with similar selectivity. The IgG in peak fractions eluted from the Ni(II)-IDA-PEVA with a stepwise concentration gradient of Tris-HCl pH 7.0 (100-700 mM) reached a purity of 98% (based on IgG, IgM, IgA, albumin, and transferrin nephelometric analysis). Adsorption IgG data at different temperatures (4-37 degrees C) were analyzed using Langmuir model resulting in a calculated maximum capacity at 25 degrees C of 204.6 mg of IgG/g of dry membrane. Decrease in Kd with increasing temperature (1.7x10(-5) to 5.3x10(-6) M) indicated an increase in affinity with increased temperature. The positive value of enthalpy change (26.2 kJ/mol) indicated that the adsorption of IgG in affinity membrane is endothermic. Therefore, lower temperature induces adsorption as verified experimentally.
authors: Department of Bioprocess Engineering, School of Chemical Engineering, State University of Campinas, UNICAMP, CP 6066, CEP 13083-970, Campinas, SP, Brazil.
authors: Mariana Borsoi
authors: MB
authors: Ribeiro
authors: Mookambesvaran
authors: M
authors: Vijayalakshmi
authors: Daniele
authors: D
authors: Todorova-Balvay
authors: Sonia Maria Alves
authors: SM
authors: Bueno
mesh_terms: D000327:Adsorption; D002021:Buffers; D002614:Chelating Agents / Q000737:chemistry; D002846:Chromatography, Affinity / Q000295:instrumentation / Q000379:methods*; D005029:Ethylenediamines / Q000737:chemistry*; D006801:Humans; D007098:Imino Acids / Q000737:chemistry*; D007074:Immunoglobulin G / Q000302:isolation & purification*; D009532:Nickel / Q000737:chemistry*; D013696:Temperature
chemical_list: D002021:Buffers; D002614:Chelating Agents; D005029:Ethylenediamines; D007098:Imino Acids; D007074:Immunoglobulin G; C099539:tris(2-aminoethyl)amine; D009532:Nickel; C008109:iminodiacetic acid