Cystatins are cysteine protease inhibitors (CPIs), prominent in many helminths.
In Brugia malayi. Bm-CPI-1 is expressed only in the mosquito stage (upper panel), and Bm-CPI-2 throughout the life cycle (including mammalian stages, lower panel (Figure from Bill Gregory )
B. malayi CPI-2 is a bifunctional inhibitor with two active sites
Schematic Representation
Maizels Lab Publications
Manoury, B., Gregory, W.F., Maizels, R.M. and Watts, C. (2001). Bm-CPI-2, a cystatin homolog secreted by the filarial parasite Brugia malayi, inhibits class II MHC-restricted antigen processing. Current Biology 11: 447-451.
Gregory, W.F. and Maizels, R.M. (2008). Cystatins from filarial parasites: evolution, adaptation and function in the host-parasite relationship. International Journal of Biochemistry & Cell Biology 40: 1389-1398.
Murray, J., Manoury, B., Balic, A., Watts, C. and Maizels, R.M. (2005). Bm-CPI-2, a cystatin from Brugia malayi nematode parasites, differs from C.elegans cystatins in a specific site mediating inhibition of the antigen-processing enzyme AEP. Molecular and Biochemical Parasitology 139: 197-203.