CD151 is a member of the tetraspanin family of transmembrane proteins, expressed in almost all cell types and tissues.[1, 2] The large extracellular loop (LEL) of CD151 is involved in protein-protein interactions that regulate cell adhesion, motility and proliferation and has been found to participate in nearly all stages of cancer progression.[3-5] The LEL of CD151 exhibits high sequence variability from other tetraspanins and it has been shown that cancer metastasis is inhibited by anti-CD151 antibodies. This makes the LEL an attractive target for the development of inhibiting compounds that are selective for CD151.[6]
In spite of the numerous in vivo studies of CD151, structural information on the LEL is limited. After trialling many expression methods to produce recombinant LEL, I have been able to produce protein. I present here conformational and stability studies of the monomeric protein.