TAMRA-ShK

TMR-ShK is a fluorescent (red) derivative of the well-known ShK toxin (Stichodactyla helianthus neurotoxin) isolated from the venom of the Carribean sea anemone Stoichactis helianthus. Wild-type ShK blocks potently Kv1.3 (KCNA3), Kv1.1 (KCNA1), Kv1.4 (KCNA4) and Kv1.6 (KCNA6) with a Kd value of 11 pM, 16 pM, 312 pM and 165 pM, respectively. The fluorescent TMR-labeled ShK blocks Kv1.3 and Kv1.1 with Kd values of 52 pM and 397 pM, respectively. TMR-ShK can be used to identify lymphocytes expressing Kv1.3 channels such as effective memory T cells (TEM) in the case of autoimmune diseases (type 1 diabetes, mellitus or rheumatoid arthritis) which overexpress Kv1.3 channels.