Merozoite surface proteins are both integral and peripheral membrane proteinmolecules found on the surface of a merozoite. A merozoite is an early lifecycle stage of a protozoan.
Merozoite surface proteins, or MSPs, are useful in researching malaria, a disease caused by protozoans. The malaria parasite, in its asexual, blood invading stage called the merozoite stage, infects red blood cells. The MSP1 complex of surface proteins likely mediates the first interactions of the parasite with red blood cells.
^Kadekoppala, Madhusudan; Holder, Anthony A (15 Aug 2010). "Merozoite surface proteins of the malaria parasite: The MSP1 complex and the MSP7 family". International Journal for Parasitology. 40 (10): 1155–1161. doi:10.1016/j.ijpara.2010.04.008.