Gram-negative E. coli is regularly used as the first choice host for DNA cloning, small-scale protein expression, and large-scale protein production for US FDA approved biologics. One of the major limitations, however, is the lipopolysaccharide (LPS) component of the outer membrane is an endotoxin. The endotoxin requires extensive and expensive removal during protein purification, according to a study published in Protein Science.
Lucigen’s research-only product, called CleanColi, may enable bioprocessors that were previously reluctant to use E. coli because of the cost, time and yield loss associated with endotoxin removal.
The company incorporated genetic deletions that alter the LPS of E.Coli into a different molecule, Lipid IVA, which allows the cells to express protein without generating endotoxins. Cell-based assays can then be performed without concern that LPS contamination could be masking the results. Simple IMAC-column purification is sufficient in most cases to prevent contamination, according to a poster on the cell lines.
Curtis Knox, VP of marketing and sales at Lucigen told BioPharma-Reporter.com the company is selling kits of the CleanColi cells to mostly large biopharma companies, specifically those doing protein expression for biologics.
“This could change the way downstream large batch production is performed for major pharma companies,” though no companies have scaled up to large-scale production yet, he said.
When grown to sufficient densities, CleanColi cells can produce similarly high protein levels as the standard BL21 cells when comparing equal numbers of cells.
As far as drawbacks, Knox told us the cell modified cell lines “grow a little slower but that’s minor in the grand scheme in the time it takes to get to an end goal,” and they still produce “as much protein as the more common strain.”
Under a recently announced partnership, RCT (Research Corporation Technologies) will be responsible for the CleanColi commercial licensing programs. RCT also owns the patent for the cell lines, Knox told us.
He added that the company is looking to produce additional E. Coli strains for plasmid production and phage display applications.
“There are other E coli strains best used for plasmid production, such as the K-12 strain, which we’re doing now by introducing the same mutations to produce plasmids that will be endotoxin free,” Knox said. He said he expects the K-12 strain to be available around November, while the phage will be ready in 2014.