Fractionation of recombinant tumor necrosis factor using hydrophobic and hydrophilic membranes.
Recombinant tumor necrosis factor (TNF) is expressed in Escherichia coli as a soluble intracellular protein. A purification process is described that incorporates a hydrophilic membrane (cellulosic) separation followed by a hydrophobic one (PTFE). The hydrophilic step is a traditional one in that species are separated primarily on the basis of size. The hydrophobic step separates species on the basis of parameters apparently not related to size. By combining these two steps, an increase in TNF purity of 7-10-fold can be achieved with a yield of 50%. The effects of cellular debris and pH on selectivity and recovery of the hydrophobic filtration step are discussed.
Cetus Corporation, Emeryville, California 94608.
G
G
Dorin
J
J
Thomson
W
W
Hanisch
D002498:Centrifugation; D005591:Chemical Fractionation / Q000379:methods; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005374:Filtration / Q000295:instrumentation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D011138:Polytetrafluoroethylene; D011994:Recombinant Proteins / Q000302:isolation & purification; D014409:Tumor Necrosis Factor-alpha / Q000302:isolation & purification*
D008567:Membranes, Artificial; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D011138:Polytetrafluoroethylene