Effect of waterborne strontium on calcium-dependent proteases in fish

Intracellular proteolysis in Atlantic salmon Salmo salar fingerlings (0+) from different biotopes in an Arctic river (Varzuga River, White Sea Basin)

“…Calpain activity units were defined as the change in optical density (Е 280 ) over a 30 min incubation and taken as 1 IU. After chromatographic separation of the salmon fingerling homogenates, fish calpains with μM and mM sensitivity to calcium were detected, which can be identified as homologues of mammalian μ-calpain and m-calpain (Salem and others 2005; Bondareva and others 2006).…”

“…Three distinct protein fractions exhibiting calcium-dependent proteolytic activity and differing in calcium sensitivity were identified in salmon fingerling homogenates (Nemova and others 2014). Fish calpains with μM and mM calcium sensitivity can be identified as homologues of mammalian µ-calpain and m-calpain, respectively, and the low-molecular component is a catalytically active subunit of the named calpains (Sorimachi and Suzuki 2001; Bondareva and others 2006).…”