Lipopolysaccharide removal affinity matrices based on novel cationic amphiphilic peptides

Abstract

Lipopolysaccharide (LPS) is one of the most challenging contaminants in biopharmaceutical industries. Cationic amphiphilic peptides (CAPs) -based affinity matrices can be potent tools for LPS removal in such situations. In this study, two newly designed CAPs derived from the LPS binding site of factor C of horseshoe crab S3E3 and S3E3A were immobilized chemo-selectively on diaminodipropylamine (DADPA) and iodoacetyl functionalized Sepharose beads. Both peptides were immobilized via their carboxyl or sulfhydryl (thiol) groups by amide or thioether bonds, respectively. The generated four affinity matrices were used to remove LPS from bovine serum albumin (BSA). The effects of different influential factors including pH, NaCl, Ethylenediaminetetraacetic acid (EDTA), and LPS concentrations on LPS removal efficiency and protein recovery were investigated by Plackett Burman (PB) method. Statistical analysis revealed that immobilized S3E3 removed LPS more effectively than immobilized S3E3A. Increasing pH and LPS concentration had negative effects on LPS removal efficiency and protein recovery. Increasing NaCl concentration improved protein recovery but reduced LPS removal efficiency. Other factors such as EDTA and type of buffer had no significant effect on the measured responses.