Schistosoma mansoni calpain large subunit (SmCalp1 (also known as Sm-p80))

The Schistosoma mansoni calpain large subunit is a calcium-dependent cysteine protease forming part of a heterodimeric enzyme complex critical for parasite survival. Two homologs, SmCalp1 (also known as Sm-p80) and SmCalp2, are present in the S. mansoni surface (tegument), with SmCalp1 being extensively characterized. This subunit contains characteristic protease domains (PC1, PC2), a membrane association domain (CBSW), and a C-terminal calcium-binding domain (PEF), all required for catalytic activity and substrate binding. Schistosome calpains degrade host proteins, such as fibronectin, contributing to immune evasion, survival, and possibly blood feeding. Targeting the large subunit with inhibitors like E64c impairs parasite viability, underscoring its therapeutic relevance and making it a target of transmission-blocking vaccines and diagnostic efforts.

Other names

SmCalp1Sm-p80Calpain large subunit (S. mansoni)Smp_214190 (gene annotation for SmCalp1)Smp_157500 (previous gene annotation for SmCalp1)Calpain catalytic domain-containing protein

Inhibition of protease activity, leading to interference with parasite survival or maintenance of host interaction surface