HELSS

HELSS is a potent, irreversible, mechanism-based inhibitor of Ca²⁺-independent PLA₂ (70% inhibition at 100 nM). It possesses a 1000-fold selectivity for Ca²⁺-independent PLA₂ vs. Ca²⁺-dependent PLA₂ . It has been used to identify the PLA₂ involved in the release of arachidonate induced by vasopressin stimulation of A-10 smooth muscle cells (IC₅₀=1 µM). It has also been shown to inhibit the Mg²⁺-dependent phophatidate phosphohydrolase from P388D1 macrophages (IC₅₀~8 µM).