Overview
- Chow, C.Y. et al. (2015) Toxins 7, 2494.
Alomone Labs Phlo1a inhibits the current of NaV1.7 channels expressed in Xenopus oocytes.A. Time course of Phlo1a (#STP-350) inhibition of NaV1.7 channel current. Membrane potential was held at -100 mV, current was elicited by a 100 ms voltage step to -10 mV delivered every 10 sec, and inhibited by 0.2 µM and 1 µM Phlo1a (bars), applied for 5 min and 2.5 min, respectively. B. Superimposed traces of NaV1.7 channel current upon application of control, 0.2 µM and 1 µM Phlo1a (as indicated), taken from the recording shown in A.
Phlo1a is a voltage-gated NaV1.7 channel blocker. It is a peptide toxin originally isolated from the venom of the Australian Phlogius sp. Tarantula. It inhibits the channel’s activation through interaction with one or more voltage-sensor domains. Phlo1a inhibits human NaV1.7 channels in a concentration-dependent manner with an IC50 value of 459 nM1.
Phlo1a is 35-residue peptide that belongs to the NaSpTx family and is considered to be a valuable research tool and a lead molecule for the development of ion channel therapeutics. To date, twelve families of NaSpTx have been recognized. Phlo1a belongs to the NaSpTx2 family and contains three disulfide bonds. The majority of tarantula-venom peptides share a highly stable inhibitor cystine knot (ICK) fold that provides resistance to chemical and thermal degradation1.
There are nine mammalian subtypes of voltage-gated sodium (NaV) channels: NaV1.1–NaV1.9. They are transmembrane proteins responsible for propagating action potentials in excitable cells, most notably nerves and muscle. These channels are considered to be important therapeutic targets for a wide variety of pathophysiological conditions such as chronic pain, cardiac arrhythmia, and epilepsy1,2.
