8.C.4. The Macrolide Bisolyngbyaside Inhibitors of Ca2+-ATPases (BLS) Family
Biselyngbyasides (BLSs), macrolides from marine cyanobacteria, are cytotoxic natural products that are high affinity (Ki approximately 10 nM) inhibitors of Ca2+-pumps with a unique binding mode. The crystal structures of the Ca2+-pump in complex with BLSs at 3.2-3.5 A-resolution show that BLSs bind to the
pump near the cytoplasmic surface of the transmembrane region. The crystal structures and activity measurement of BLS analogs reveal the structural features that confer high potency to BLSs as inhibitors of the pump (Morita et al. 2015).