Purification and characterization of lipopolysaccharide induced TNF-like factor from rabbit serum

A TNF-like factor was purified from lipopolysaccharide (LPS) induced New Zealand white rabbit serum. The TNF-like factor was purified by DEAE-Sephacel, Sephacryl S-200, Mono-Q, CM-affi gel Blue, Superose 12 H/R preparative columns to the specific activity of 4 x 10(6) U/mg protein. The purified protein was 45 kDa in its oligomeric form and 22 kDa in its monomeric form. Rabbit TNF-like factor had a pI value of 5.0 and was resistant to trypsin digestion. The TNF-like factor reacted with polyclonal-Ab against human TNFalpha on immunoblot and immunoprecipitation analysis and interacted with human TNF receptors. Taken together, rabbit TNF-like factor might be a high molecular weight form of rabbit TNFalpha.