Virtual screening of targeted acrylamide warheads for identification of covalent inhibitors of Cryptopain, a cysteine protease of Cryptosporidium parvum

Cryptosporidiosis is an infection induced by the single-celled protozoan Cryptosporidium parasite. This parasite commonly infects the intestines of humans and animals, leading to gastrointestinal symptoms such as diarrhea, stomach cramps, nausea, and vomiting. Cryptopain protein, a type of cysteine protease found in the genome of Cryptosporidium parvum plays an important role in cell invasion and its survival. In this study, we mainly focused on the structural validation and reliability of docking aspects of the Cryptopain protein of C. parvum. The best-modeled structure of Cryptopain protein was run in a water environment through a 200 ns Molecular Dynamics (MD) simulation study. We employed a covalent docking scheme to screen suitable inhibitors against our target protein. Furthermore, the reliability of the binding mode for the best possible inhibitors was validated at a 100 ns time frame through a complex MD simulation study. From docking and simulation studies, we found Z3952175270 as a possible inhibitor on the basis of docking score and binding affinity for the possible binding site in the Cryptopain protein. Our findings highlight the potential of targeting Cryptopain protein with specific inhibitors, which could pave the way for the development of novel therapeutic strategies against cryptosporidiosis. This work contributes to the field by providing a deeper understanding of the molecular interactions involved in Cryptopain inhibition, potentially leading to effective treatments for a disease that significantly impacts public health, particularly in immunocompromised individuals and in areas with limited access to clean water.