RPRFamide is a toxin from the carnivorous marine cone snail Conus textile, a predatory species that mainly lives in tropical waters.

[3] The short length, the C-terminal Arg–Phe–NH2 (RFa) motif, and the lack of cysteines clearly distinguishes these peptides from conotoxins and categorises them as cono-RFamides.

[5] The peptide delays the desensitization of ASIC3 channels, keeping them open longer and allowing sustained ion flow, which increases sensitivity to pain stimuli and prolongs the nociceptive effect.

These receptors are ligand-gated ion channels that mediate fast synaptic transmission in the nervous system and are involved in neuromuscular function.

[3] The toxin's inhibitory effect prevents the influx of ions that would normally result from acetylcholine binding, disrupting neurotransmission and impairing muscle contraction, depending on the receptor subtype.