GPAnt-2 peptide

GPAnt-2 peptide

• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

Pyr-QwFwwM-NH2, w=D-Trp

pGlu-Gln-D-Trp-Phe-D-Trp-D-Trp-Met-NH2

7

95.22%

C₅₇H₆₄N₁₂O₉S

1093.25

143675-79-0

71308571

Synthetic

Powder

GPAnt-2, has the amino acid sequence pGlu-Gln-D-Trp-Phe-D-Trp-D-Trp-Met-NH2, is a G-Protein antagonist peptide.
GPAnt-2 inhibited the activation of G proteins (Gi or Go) by M2 muscarinic cholinergic receptor (M2 mAChR) or of Gs by β-adrenergic receptor in the reconstituted phospholipid vesicles, as measured by receptor-promoted GTP hydrolysis.
The inhibition by GPAnt-2 was apparently reversible and competitive with respect to receptor binding to G proteins. The inhibition could be overcome by increasing the concentration of receptor in the vesicles and was not altered by changes in the concentration of G protein, suggesting that the peptide competes with the receptor for interaction with G proteins.
GPAnt-2 did not interfere with the binding of ligands to the receptor or the interaction of G protein and guanine nucleotide.
GPAnt-2 can be used as a tool to study the receptor-G protein interaction. For example, it was used to analyze the effect of an agonist on receptor-G protein coupling, and the results suggested that an agonist enhances the productive interaction between receptor and G protein by increasing the efficacy of coupling, not by increasing the affinity between receptor and G protein.

Normally, this peptide will be delivered in lyophilized form and should be stored in a freezer at or below -20 °C. For more details, please refer to the manual: Handling and Storage of Synthetic Peptides

• Mukai H, Munekata E, Higashijima T. G protein antagonists. A novel hydrophobic peptide competes with receptor for G protein binding. J Biol Chem. 1992 Aug 15;267(23):16237-43. PMID: 1379592.

Trifluoroacetic acid (TFA) has a significant impact on peptides due to its role in the peptide synthesis process.

TFA is essential for the protonation of peptides that lack basic amino acids such as Arginine (Arg), Histidine (His), and Lysine (Lys), or ones that have blocked N-termini. As a result, peptides often contain TFA salts in the final product.

TFA residues, when present in custom peptides, can cause unpredictable fluctuations in experimental data. At a nanomolar (nM) level, TFA can influence cell experiments, hindering cell growth at low concentrations (as low as 10 nM) and promoting it at higher doses (0.5–7.0 mM). It can also serve as an allosteric regulator on the GlyR of glycine receptors, thereby increasing receptor activity at lower glycine concentrations.

In an in vivo setting, TFA can trifluoroacetylate amino groups in proteins and phospholipids, inducing potentially unwanted antibody responses. Moreover, TFA can impact structure studies as it affects spectrum absorption.