Description
IL-1 is a name that designates two proteins, IL-1a and IL-1b, that are the products of distinct genes, but recognize the same cell surface receptors. Both proteins are produced by a wide variety of cells in response to stimuli such as those produced by inflammatory agents, infections, or microbial endotoxins. The proteins are synthesized as 31 kDa precursors that are subsequently cleaved into proteins with molecular weights of approximately 17.5 kDa. Mature human and mouse IL-1b share approximately 75% amino acid sequence identity and human IL-1b has been found to be active on mouse cell lines. IL-1a and IL-1b are potent pro-inflammatory cytokines that induce a wide variety of biological activities on different cell types. The 153 amino acid residue methionyl form of the recombinant protein has a predicted molecular mass of approximately 17 kDa