Overview
The product is soluble in pure water at high micromolar concentrations (100 µM - 1 mM). For long-term storage in solution, we recommend preparing a stock solution by dissolving the product in double-distilled water (ddH2O) at a concentration between 100-1000x of the final working concentration. Divide the stock solution into small aliquots and store at -20°C. Before use, thaw the relevant vial(s) and dilute to the desired working concentration in your working buffer.
Centrifuge all product preparations before use. It is recommended to prepare fresh solutions in working buffers just before use. Avoid multiple freeze-thaw cycles to maintain biological activity.
Kappa-lycotoxin-Os1a (Osu1 Toxin) is a 64-amino acid peptidyl toxin derived from the venom of the spider Oculicosa supermirabilis1. Osu1 exhibits inhibitory activity at the hKv1.5 channel and slows the activation kinetics of the Kv1.5 current at ~µM peptide concentration. The mode of action of Osu1 toxin involves binding to the voltage-sensing domain of the hKv1.5 potassium channel rather than occluding its pore. This binding effectively prevents the channel's opening at physiological membrane potentials, resulting in the inhibition of the ultra-rapid delayed rectifier potassium current (IKur). Consequently, this prolongs atrial action potentials, potentially leading to the termination of atrial fibrillation (AF)1,2.
The hKv1.5 channel is selectively expressed in human atrial myocytes and is absent in ventricular tissues, reducing the likelihood of ventricular side effects. Osu1 toxin demonstrates a high affinity for hKv1.5, and this specificity makes it a promising candidate for selective AF therapies1,2.
The potential applications of Osu1 toxin extend beyond AF. Its unique properties make it a valuable tool for studying ion channel physiology and hold promise for the development of toxin-based therapeutics. Osu1's ability to prolong atrial action potentials without affecting ventricular tissues further highlights its therapeutic relevance1,2.
