Crosstide peptide

Crosstide peptide

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

Batch to batch variation of the purity

H-GRPRTSSFAEG-OH

H-Gly-Arg-Pro-Arg-Thr-Ser-Ser-Phe-Ala-Glu-Gly-OH

11

95.92%

C₄₈H₇₇N₁₇O₁₇

1164.22

Synthetic

Powder

Crosstide is a synthetic peptide derived from glycogen synthase kinase-3β (GSK-3). Crosstide functions as substrate for Akt/PKB (protein kinase B) and is also recognized by MAPKAP kinase-1 and p70S6K, Crosstide also displays similar selectivity towards PKBα, PKBβ and PKBγ isoforms. The fluorescent and biotinylated versions of crosstide demonstrate similar enzymic activity.

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

• Dai (2002) Human serum and glucocorticoid-inducible kinase-like kinase (SGKL) phosphorylates glycogen syntheses kinase 3 beta (GSK-3β) at serine-9 through direct interaction Biochem. Biophys. Res. Comm. 293 (4) 1191 PMID: 12054501
• Baer et al (2005) Activation of a GST-tagged AKT2/PKBbeta. Biochim. Biophys. Acta 1725(3) 340 PMID: 15890450
• Xu et al (2005) WNK1 Activates SGK1 by a Phosphatidylinositol 3-Kinase-dependent and Non-catalytic Mechanism. J. Biol. Chem. 280 34218 PMID: 16081417

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.