NF-kappa B protein purification from bovine spleen: nucleotide stimulation and binding site specificity

The activity of the enhancer for the kappa immunoglobulin light chain gene critically depends on the presence in the nucleus of the NF-kappa B protein. We purified NF-kappa B over 50,000-fold and identified two protein species, 42 and 44 kDa, that could be eluted and renatured from a sodium dodecyl sulfate/polyacrylamide gel to give specific DNA-binding activity. Binding of the purified bovine NF-kappa B as well as that from human and murine B- or T-lymphoid cell extracts was dramatically stimulated by nucleoside triphosphates. This effect distinguished NF-kappa B from a related factor, H2-TF1. Purified NF-kappa B interacted efficiently with regulatory sequences that function during either B- or T-lymphocyte activation, including the human immunodeficiency virus enhancer and a NF-kappa B binding site we detected in the interleukin 2 enhancer.