Endotoxin Removal during the Purification Process of Human-like Collagen

Interaction between human-like collagen (HLC) and endotoxin makes endotoxin removal from HLC more complicated. In this study, a simple, effective, and low-cost method was developed for endotoxin removal. A 0.4% (volume fraction) TritonX-100 solution was used to dissociate the HLC-endotoxin complexes and Q XL resin was used to remove endotoxin from the HLC solution. Product solution containing 1.2 mg · ml−1 HLC in Tris-HCl buffer (pH 7.5) and 50 mM NaCl was added to the Q XL resin; the endotoxin removal efficiency was more than 98% and HLC recovery of up to 95% could be obtained; HLC purity was also enhanced after this process. The residual TritonX-100 was removed by using a superdex-200 column. This method greatly reduced the cost of purification but provided high endotoxin removal efficiency and HLC recovery.