CoPoP

CoPoP is a phosphatidylcholine containing palmitic acid at the sn-1 position and cobalt-bound porprin at the sn-2 position.¹ It has been used in the generation of liposomes in which cobalt in the porprin moiety located in the drophobic bilayer coordinates with the imidazole group in histidine residues to capture His-tagged proteins and peptides. Liposomes containing CoPoP bound to a His-tagged form of the HIV glycoprotein 41 (gp41) envelope protein membrane proximal external region (MPER) and encapsulating the toll-like receptor 4 (TLR4) agonist monophosphoryl lipid A induces viral titers in immunocompetent, but not atmic, mice, which is further increased by a booster injection indicating a T cell-mediated memory response. Liposomes containing CoPoP bound to other His-tagged peptides and other factors have been used to reduce tumor growth and metastasis in murine cancer models and parasite transmission in a P. falciparum-induced mouse model of malaria, as well as to induce neutralizing antibodies in mice and rabbits in models of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.^2,3,4