The name of piscivorin comes from the snake species name piscivorus, which is derived from the Latin words pisces and vorare, meaning 'fish' and 'to devour' respectively.
The nucleotide sequence of piscivorin cDNA spans 1323 bp, containing an open reading frame of 240 codons.
[3] Since caffeine normally causes contraction through the release of Ca2+ from the sarcoplasmic reticulum, this differential effect indicates that piscivorin is an L-type calcium channel blocker.
At a concentration of 1 μM, its effect on depolarization-induced smooth muscle contraction is weaker than of the related CRISP family toxins ablomin, triflin or latisemin.
A sequence comparison of piscivorin and other CRISP family proteins suggests that the Glu186 residue is the crucial site for the blocking of the calcium channels.