hemichannel

Gap19 is a peptide that corresponds to a sequence on the cytoplasmic loop (CL) of Cx43.

TAT-Gap19 acetate is a specific inhibitor of connexin43 hemichannel (Cx43 HC). TAT-Gap19 acetate traverses the blood-brain barrier and alleviates liver fibrosis in mice. TAT-Gap19 acetate does not inhibit the corresponding Cx43 GJCs.

Cx43 HC-IN-1 (Compound D4) is a selective, orally active inhibitor of connexin hemichannels (Cx43 HC). It effectively suppresses hemichannel activity mediated by Cx43/Cx45 in denervated skeletal muscle fibers, significantly enhancing neuronal reinnervation of muscle fibers. By inhibiting hemichannels in brain glial cells, Cx43 HC-IN-1 reduces neuroinflammation and neuronal hyperexcitability, alleviating seizures in mice. It is applicable for research on epilepsy and muscular disorders.

TAT-Gap19(I130A) is a control peptide for TAT-Gap19, a Cx43 hemichannel blocker. TAT-Gap19(I130A) consists of TAT-GAP19 with a I130A amino acid residue change at a key residue for GAP19 activity. In C6 glioma cells expression Cx43, TAT-GAP19(1130A) does not inhibit [Ca2+]i-triggered ATP release at 200 μM. TAT-Gap19(I130A) is cell permeable.

TAT-Gap19 TFA, a Cx mimetic peptide and specific connexin43 hemichannel (Cx43 HC) inhibitor, does not inhibit corresponding Cx43 gap junction channels (GJCs). It crosses the blood-brain barrier and has shown efficacy in alleviating liver fibrosis in mice [1] [2] [3].

Tat-Gap 19, a peptide inhibitor of connexin43 (Cx43) hemichannels, is derived from the HIV-1 Tat protein transduction domain fused with a nine-amino acid sequence from Cx43 residues 128-136. This compound, at a concentration of 10 µM, effectively suppresses glutamate-induced ATP release in primary rat hepatocytes, indicating inhibition of Cx43 hemichannel activity. Furthermore, Tat-Gap 19 demonstrates therapeutic potential by significantly reducing infarct volume in a mouse cerebral ischemia-reperfusion injury model following middle cerebral artery occlusion (MCAO) at a dosage of 25 mg/kg. Moreover, its intraperitoneal administration at 1 mg/kg per day ameliorates fibrosis and decreases the area of hepatic stellate cells, the precursors to myofibroblasts, expressing α-smooth muscle actin (α-SMA), in a model of thioacetamide-induced liver damage. Additionally, it enhances superoxide dismutase (SOD) activity in hepatic cells from the treated mice, indicating its antioxidative benefits.

ALMB-0168 is an agonistic antibody targeting the Cx43 hemichannel and has been shown to suppress tumor growth.

Cx43 hemichannel blocker (IC50 ~7 μM). No significant affinity for gap junctions or Panx1 channels. N-terminal transactivator of transcription (TAT) motif promotes membrane permeability and increases inhibitory effect of Gap19. Active in vivo. Brain penet