Chemokine structure. (A) Three-dimensional structures of IL-8 and MCP-1 monomers. The three β-pleated sheets of IL-8 are easier to appreciate than those of MCP-1 and are indicated. (B) Three-dimensional structures of IL-8 and MCP-1 dimers. The profound difference in dimer structure is indicated. For MCP-1 and other CC chemokines, dimerization near the N-terminus involves a short, so-called β0 sheet which is indicated.119,120 Reprinted with permission from Rollins BJ: Monocyte chemoattractant protein 1: A potential regulator of monocyte recruitment in inflammatory disease. Molecular Medicine Today, vol 2, p 198, 1996.266