Ca^(2+)-亚氨二醋酸金属离子亲和色谱法吸附内毒素(英文)  

Adsorption of endotoxins on Ca^(2+)-iminodiacetic acid by metal ion affinity chromatography

作　　者：André Moreni LOPES Jorge Sánchez ROMEU Rolando Páez MEIRELES Gabriel Marquez PERERA Rolando Perdomo MORALES Adalberto PESSOA Lourdes Zumalacárregui CáRDENAS 

机构地区：[1]Department of Biochemical and Pharmaceutical Technology,School of Pharmaceutical Sciences,University of So Paulo(FCF/USP) [2]Purification Development Department,Center for Genetic Engineering and Biotechnology(CIGB) [3]Center for Pharmaceuticals Research and Development(CIDEM) [4]Higher Polytechnic Institute José Antonio Echeverría(CUJAE)

出　　处：《色谱》2012年第11期1194-1202,共9页Chinese Journal of Chromatography

基　　金：supported by grants from the Brazilian Agency Coordination of Graduate Level Training(CAPES,project 0366/09-9);State of So Paulo Research Support Foundation(FAPESP-Brazil,project 2005/60159-7)

摘　　要：Endotoxins(also known as lipopolysaccharides(LPS)) are undesirable by-products of recombinant proteins,purified from Escherichia coli.LPS can be considered stable under a wide range of temperature and pH,making their removal one of the most difficult tasks in downstream processes during protein purification.The inherent toxicity of LPS makes their removal an important step for the application of these proteins in several biological assays and for a safe parenteral administration.Immobilized metal affinity chromatography(IMAC) enables the affinity interactions between the metal ions(immobilized on the support through the chelating compound) and the target molecules,thus enabling high-efficiency separation of the target molecules from other components present in a mixture.Affinity chromatography is applied with Ca2+-iminodiacetic acid(IDA) to remove most of the LPS contaminants from the end product(more than90%).In this study,the adsorption of LPS on an IDA-Ca2+ was investigated.The adsorption Freundlich isotherm of LPS-IDA-Ca2+ provides a theoretical basis for LPS removal.It was found that LPS is bound mainly by interactions between the phosphate group in LPS and Ca2+ ligands on the beads.The factors such as pH(4.0 or 5.5) and ionic strength(1.0 mol/L) are essential to obtain effective removal of LPS for contaminant levels between endotoxin' concentration values less than100 EU/mL and 100 000 EU/mL.This new protocol represents a substantial advantage in time,effort,and production costs.Endotoxins（also known as lipopolysaccharides（LPS）） are undesirable by-products of recombinant proteins,purified from Escherichia coli.LPS can be considered stable under a wide range of temperature and pH,making their removal one of the most difficult tasks in downstream processes during protein purification.The inherent toxicity of LPS makes their removal an important step for the application of these proteins in several biological assays and for a safe parenteral administration.Immobilized metal affinity chromatography（IMAC） enables the affinity interactions between the metal ions（immobilized on the support through the chelating compound） and the target molecules,thus enabling high-efficiency separation of the target molecules from other components present in a mixture.Affinity chromatography is applied with Ca2＋-iminodiacetic acid（IDA） to remove most of the LPS contaminants from the end product（more than90%）.In this study,the adsorption of LPS on an IDA-Ca2＋ was investigated.The adsorption Freundlich isotherm of LPS-IDA-Ca2＋ provides a theoretical basis for LPS removal.It was found that LPS is bound mainly by interactions between the phosphate group in LPS and Ca2＋ ligands on the beads.The factors such as pH（4.0 or 5.5） and ionic strength（1.0 mol/L） are essential to obtain effective removal of LPS for contaminant levels between endotoxin＇ concentration values less than100 EU/mL and 100 000 EU/mL.This new protocol represents a substantial advantage in time,effort,and production costs.

关 键 词：immobilized metal affinity chromatography(IMAC) lipopolysaccharides(LPS) endotoxin removal recombinant proteins isotherms protein purification 

分 类 号：O658[理学—分析化学]