Name: µ-TRTX-Df1a
Brand: Alomone Labs
SKU: STD-050

Overview

Cat #: STD-050

Alternative Name Mu-TRTX- Df1a, Mu-theraphotoxin-Df1a, Df1a

Lyophilized Powder yes

Origin Davus fasciatus (Costa Rican tiger rump) (Cyclosternum fasciatus)

Source Synthetic peptide

MW: 4078.6 Da

Purity: >98%

Form Lyophilized Powder

Effective concentration 20 nM – 0.5 µM

Sequence ECRWFLGGCSGGQTCCEHLVCHRKHQWCVWDWSF – NH₂

Modifications Phe³⁴ - C-terminal amidation
Disulfide bonds location- Cys²-Cys¹⁶, Cys⁹-Cys²¹, Cys¹⁵-Cys²⁸

Structure

Molecular formula C₁₈₀H₂₄₆N₅₄O₄₅S₆

Activity Df1a exhibits a rank order of potency for hNa_V channels as follows: 1.7 > 1.2 > 1.3 > 1.6 > 1.1 > 1.4 > 1.5, and for hCa_V3 channels, the order is 3.1 > 3.3 > 3.2. Also, Df1a demonstrates a dual modulatory effect by simultaneously inhibiting peak current and slowing fast inactivation of Na_V1.1, Na_V1.3, and Na_V1.5 subtypes¹.

References-Activity

Cardoso, F.C. et al. (2017) Br. J. Pharmacol. 174, 2528.

Accession number P0DPC2

Shipping and storage Shipped at room temperature. Product as supplied can be stored intact at room temperature for several weeks. For longer periods, it should be stored at -20°C. Protect from light and moisture.

Solubility Soluble in water. For long-term storage in solution, we recommend to prepare a stock solution by dissolving the product in double distilled water (ddH₂O) at a concentration X100-1000 of final working solution. Divide the solution into small aliquots and store at -20°C. Upon use, thaw the relevant vial intended for use and dilute in your desired working buffer. The preparation of fresh solutions in working buffers before use is recommended. Repeat freeze-thawing might result in loss of activity. Centrifuge all product preparations before use (10000 x g, 5 min).

Storage of solutions The reconstituted solution can be stored at 4°C for up to 1 week. For longer periods (up to 6 months), small aliquots should be stored at -20°C. We do not recommend storing the toxin in working solutions for longer than a few days. Avoid multiple freeze- thaw cycles.

Our bioassay

Alomone Labs µ-TRTX-Df1a inhibits Na_V1.7 channel currents heterologously expressed in Xenopus oocytes.
A. Representative time course of µ-TRTX-Df1a (#STD-050) inhibition of Na_V1.7 channels current. Membrane potential was held at -100 mV, current was elicited by a 100 ms voltage step to 0 mV every 10 sec, and significantly inhibited by application of 50 nM µ-TRTX-Df1a (green).
B. Superimposed traces of Na_V1.7 channel currents in the absence (control) and presence (green) of 50 nM µ-TRTX-Df1a (taken from the recording in A).

References - Scientific background

Cardoso, F.C. et al. (2017) Br. J. Pharmacol. 174, 2528.
Lory, P. et al. (2020) Pflugers Arch – Eur. J. Physiol. 472, 831.
Chow, C.Y. et al. (2015) Toxins 7, 2494.
Klint J.K. et al. (2015) Br. J. Pharmacol. 172, 2445.

Scientific background

µ-TRTX-Df1a (Df1a) is a 34-amino acid peptide toxin originally isolated from the venom of the tarantula Davus fasciatus. This toxin has been identified as a potent blocker of voltage-gated sodium (Na_V) and calcium (Ca_V)3 channels¹. Df1a exhibits a rank order of potency for hNaV channels as follows: 1.7 > 1.2 > 1.3 > 1.6 > 1.1 > 1.4 > 1.5, and for hCa_V3 channels, the order is 3.1 > 3.3 > 3.2. Additionally, Df1a demonstrates a dual modulatory effect by simultaneously inhibiting peak current and slowing fast inactivation of Na_V1.1, Na_V1.3, and Na_V1.5 subtypes. It also alters the voltage dependence of activation and inactivation for most Na_V subtypes¹.

Df1a belongs to the Family 2 of Na_V-targeting spider toxins (NaSpTx), characterized by an inhibitor cystine knot (ICK) motif and highly conserved N- and C-terminal regions¹. ICK peptides possess a disulfide-rich structural framework that creates a "knot," imparting exceptional structural, thermal, and proteolytic stability.

Ca_V3 are T-type, low voltage-gated calcium channels. Their electrophysiological properties include low voltage thresholds for activation and inactivation, rapid inactivation, and rebound bursting. These properties are responsible for the Ca_V3-mediated fine-tuned regulation of neuronal excitability in both the central nervous system (CNS) and peripheral nervous system (PNS)².

Nav channels are involved in a wide array of physiological processes. There are nine mammalian subtypes of voltage-gated sodium (Na_V) channels: Na_V1.1–Na_V1.9. 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 epilepsy^3,4.

Df1a acted as an analgesic in vivo, alleviating the spontaneous pain behaviors triggered by the Na_Vactivator OD1¹.

Target Na_V channels and T-type Ca²⁺ channels

Lyophilized Powder

µ-TRTX-Df1a (#STD-050) is a highly pure, synthetic, and biologically active peptide toxin.

Certificate of Analysis SDS

For research purposes only, not for human use

Last Update: 04/11/2024

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µ-TRTX-Df1a

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Scientific Background

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