G Protein Alpha i Inhibitor (Tat-GPR)

The Tat-GPR peptide was designed to functions as a guanine nucleotide dissociation inhibitor (GDI) that selectively inhibits the Gαi subunit.


  • Based on a consensus sequence of the G protein regulatory (GPR) motif of AGS3 (also known as the GoLoco motif in RGS14)
  • Highly Selective – Inhibits Gα while stimulating the activation of Gβγ signaling; Common pertussis toxin (PTX) inhibition stabilizes the entire heterotrimer
  • Cell Permeable – Fused to portion the Tat (transactivator of transcription) HIV-1 protein
  • Fast Acting – Tat-GPR works in minutes, whereas PTX inhibitors require over-night incubations

Mechanistically, GDIs are well suited to pursue receptor pharmacology of Gαi versus Gβγ signaling and their specific roles in cell signaling and disease. The Tat-GPR peptide stabilizes the GDP-bound conformation of Gαi, prevents the binding of AGS3 to Gαi subunits, blocks receptor coupling to G-protein, and Tat-GPR has shown efficacy in an in vivo model of cocaine addiction and in vitro models of cancer. Tat-GPR peptide at 100nM suppresses α2-AR associated cAMP/Gαi activity in cell culture.

From the laboratory of Yuri K. Peterson, PhD, Medical University of South Carolina.

Catalog Number Product DataSheet Size AVAILABILITY Price Qty
G Protein Alpha i Inhibitor (Tat-GPR)
200ug In stock
Regular Price:$413.00
On Sale:

Product Type: Protein
Name: Tat-GPR
Accession ID: P19086, CAS: 419535-56-1
Source: Synthetic chemistry
Molecular Weight: 4846.6 Da
Format: Powder
Purity: >95% HPLC and MS data
Solubility: Water or HEPES buffered water
Suggested Amount per Experiment: 300nM (150ng in 100uL)
Comments: Working stock=30mM
Storage: Long term -20C
Shipped: Ambient temperature

From the laboratory of Yuri K. Peterson, PhD, Medical University of South Carolina.
  1. Appleton KM, Bigham KJ, Lindsey CC, Hazard S, Lirjoni J, Parnham S, Hennig M, Peterson YK. Bioorg Med Chem. 2014 Jul 1;22(13):3423-34. PMID: 24818958
  2. Bowers MS, McFarland K, Lake RW, Peterson YK, Lapish CC, Gregory ML, Lanier SM, Kalivas PW. Neuron. 2004 Apr 22;42(2):269-81. PMID: 15091342
  3. Oxford GS1, Webb CK. GoLoco motif peptides as probes of Galpha subunit specificity in coupling of G-protein-coupled receptors to ion channels. Methods Enzymol. 2004;390:437-50. PMID: 15488193.
  4. Peterson YK, Hazard S 3rd, Graber SG, Lanier SM. Identification of structural features in the G-protein regulatory motif required for regulation of heterotrimeric G-proteins. J Biol Chem. 2002 Mar 1;277(9):6767-70. Epub 2001 Dec 27. PMID: 11756403.
  5. Peterson YK, Bernard ML, Ma H, Hazard S 3rd, Graber SG, Lanier SM. Stabilization of the GDP-bound conformation of Gialpha by a peptide derived from the G-protein regulatory motif of AGS3. J Biol Chem. 2000 Oct 27;275(43):33193-6. PMID: 10969064.
  6. Kimple RJ, Kimple ME, Betts L, Sondek J, Siderovski DP. Structural determinants for GoLoco-induced inhibition of nucleotide release by Galpha subunits. Nature. 2002 Apr 25;416(6883):878-81.
  7. M'Kadmi C, Cabral A, Barrile F, Giribaldi J, Cantel S, Damian M, Mary S, Denoyelle S, Dutertre S, Péraldi-Roux S, Neasta J, Oiry C, Banères JL, Marie J, Perello M, Fehrentz JA. N-Terminal Liver-Expressed Antimicrobial Peptide 2 (LEAP2) Region Exhibits Inverse Agonist Activity toward the Ghrelin Receptor. J Med Chem. 2019 Jan 24;62(2):965-973. View Article

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