CREBtide TFA 

CREBtide TFA is a CREB (cAMP response element binding protein)-like peptide. CREBtide TFA a synthetic 13 amino acid peptide, has been reported as a PKA substrate^[1][2][3].

delta-CREB is a spliced variant of cAMP response element binding protein (CREB). CREBtide (KRREILSRRPSYR), a synthetic peptide based on the phosphorylation sequence in delta-CREB. delta-CREB and CREBtide are tested as substrates of cAMP-dependent protein kinase (cAK). The apparent K_m of CREBtide phosphorylation by cAK is 3.9 μM, which is 10-fold lower than that of Kemptide (K_m=39 μM), the synthetic peptide substrate most often employed for cAK measurement. The V_max values are 12.4 mumol/(min.mg) for CREBtide and 9.8 mumol/(min.mg) for Kemptide. The apparent K_m of CREBtide phosphorylation by cGMP-dependent protein kinase (cGK) is 2.9 μM and the V_max value is 3.2 mumol/(min.mg). Both delta-CREB and CREBtide are phosphorylated at a much slower rate by cGK as compared with cAK, implying that the high cAK/cGK specificity exhibits by delta-CREB is retained by the peptide^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

1716.99 (free acid)

C₇₃H₁₂₉N₂₉O₁₉.xC₂HF₃O₂

Solid

White to off-white

Lys-Arg-Arg-Glu-Ile-Leu-Ser-Arg-Arg-Pro-Ser-Tyr-Arg

KRREILSRRPSYR

NCCCC[C@@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N1[C@H](C(N[C@H](C(N[C@@H](CC2=CC=C(O)C=C2)C(N[C@@H](CCCNC(N)=N)C(O)=O)=O)=O)CO)=O)CCC1)=O)CCCNC(N)=N)=O)CCCNC(N)=N)=O)CO)=O)CC(C)C)=O)[C@H](CC)C)=O)CCC(O)=O)=O)CCCNC(N)=N)=O)CCCNC(N)=N)=O)N.O=C(C(F)(F)F)O.[x]

Room temperature in continental US; may vary elsewhere.

Sealed storage, away from moisture

*In solvent : -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture)

• [1]. Wu J, et al. A microPLC-based approach for determining kinase-substrate specificity. Assay Drug Dev Technol. 2007 Aug;5(4):559-66.  [Content Brief]

  [2]. Colbran JL, et al. cAMP-dependent protein kinase, but not the cGMP-dependent enzyme, rapidly phosphorylates delta-CREB, and a synthetic delta-CREB peptide. Biochem Cell Biol. 1992 Oct-Nov;70(10-11):1277-82.  [Content Brief]

  [3]. Harum KH, et al. Cognitive impairment in Coffin-Lowry syndrome correlates with reduced RSK2 activation. Neurology. 2001 Jan 23;56(2):207-14.  [Content Brief]