Basic protein that bind to cell membrane and depolarizes cardiomyocytes. This cytotoxin also shows lytic activities, but 2-fold more important than that of CTX-A2. It binds to the integrin alpha-V/beta-3 with a moderate affinity. Inhibits protein kinase C. It may interact with sulfatides in the cell membrane, which induces pore formation and cell internalization and is responsible for cytotoxicity in cardiomyocytes. It also may target the mitochondrial membrane and induces mitochondrial swelling and fragmentation.