ABSTRACT
Objective To evaluate the effectiveness of ultrafiltration technology in endotoxin removal from purified recombinant MUC1-MBP fusion protein (MUC1-MBP)and to demonstrate the effect of ultrafiltration on endotoxin removal.Methods CM Sepharose FF weak cation exchange (CM)(CM group), CM combined with Phenyl Sepharose 6 FF exchange (C6)(CM+C6 group),CM combined with ultrafiltration (CM+ultrafiltration group), and CM combined with C6 and ultrafiltration (CM+C6+ultrafiltration group)were used to purify the MUC1-MBP from E.coli. and remove endotoxin;the expression level of endotoxin was detected by Chromogenic End-point Tachypleus Amebocyte Lysate.Results There was a single band at the expected molecular weight of 62 000 by SDS-PAGE analysis.and the purity>96% by Quantity One analysis.The endotoxin levels in CM group and CM +C6 group were quite high and there was no significant difference between two groups (P>0.05 );the endotoxin level in CM+ultrafiltration group was significantly lower than that in CM group, and there was significant difference (P0.05 ). Conclusion The effects of CM or CM combined with C6 on endotoxin removal are quite poor, especially C6;CM combined with ultrafiltration are quite effective on endotoxin removal,and ultrafiltration plays an important role in endotoxin removal.