Gap19 TFA is a nine-amino-acid peptide developed from the Cx43 cytoplasmic loop (CL) and a potent, selective connexin 43 (Cx43) hemichannel blocker. Gap19 TFA prevents the intramolecular interaction of the C terminus (CT) with CL. Gap19 TFA does not block GJ channels or Cx40/pannexin-1 hemichannels. Gap19 TFA has a protective effect on myocardium.

Physicochemical Properties

Molecular Formula	C??H??F?N??O??
Molecular Weight	1275.46
Related CAS #	Gap19;1507930-57-5
Appearance	White to off-white solid powder
Synonyms	Gap19 TFA; Gap-19 TFA
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	In 30 minutes, Gap19 TFA (250 μM) reduces the absorption of potassium in the mitochondria[1]. In HeLa-Cx43 cells, unitary hemichannel currents are inhibited by 400 μM of gap19 TFA[2]. Ventricular cardiomyocytes' hemichannel unitary currents are inhibited by Gap19 TFA at 100 μM [2]. In vitro and in vivo, Gap19 TFA (250 μM, 30 min) guards against myocardial ischemia/reperfusion injury[2].
ln Vivo	About one-fifth of the infarct size is greatly reduced by Gap19 TFA (iv; 25 mg/kg; 10 min before ligation)[2].
Animal Protocol	Animal/Disease Models: C57/BL6 black mouse[2] Doses: 25 mg/kg Route of Administration: IV; 10 min before ligation Experimental Results: Dramatically decreased the infarct size by approximately one-fifth.
References	[1]. Connexin 43 impacts on mitochondrial potassium uptake. Front Pharmacol. 2013 Jun 6;4:73. [2]. Selective inhibition of Cx43 hemichannels by Gap19 and its impact on myocardial ischemia/reperfusion injury. Basic Res Cardiol. 2013 Jan;108(1):309.

Solubility Data

Solubility (In Vitro)	May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples
Solubility (In Vivo)	Solubility in Formulation 1: 100 mg/mL (78.40 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	0.7840 mL	3.9202 mL	7.8403 mL
	5 mM	0.1568 mL	0.7840 mL	1.5681 mL
	10 mM	0.0784 mL	0.3920 mL	0.7840 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.