| Size | Price | Stock | Qty |
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| 1mg |
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| 5mg |
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| 10mg |
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| Targets |
Kemptide's primary target is the catalytic subunit of protein kinase A (PKA). PKA is a cAMP-dependent kinase that plays a fundamental role in numerous cellular functions, including the regulation of sugar metabolism, muscle contraction, heart rate, and blood pressure. Kemptide functions as a phosphate acceptor; the serine residue within its sequence (underlined in LRRASLG) is specifically phosphorylated by PKA. This phosphorylation event can be readily quantified, allowing researchers to assess kinase activity.
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| ln Vitro |
Synthetic build keptide is a substrate of protein kinase (PK) that is reliant on cAMP. In the presence of extracellular ATP and cAMP, several types of intact cells catalyze the phosphorylation of Kemptide, which has a Km value of 3–4 uM[1]. Pyruvate kinase is the source of the synthetic peptide substrate known as keteptide [2].
Kemptide is used in vitro as a substrate to measure PKA activity. In a typical assay, Kemptide is incubated with a sample containing PKA (e.g., a cell lysate or purified enzyme) in the presence of ATP, which may be radiolabeled (e.g., with [γ-32P]ATP) or unlabeled. The phosphorylation of Kemptide by PKA is then quantified. This can be done by measuring the incorporation of radioactive phosphate into the peptide, or by using a fluorescence-based or luminescence-based detection method. Its high specificity for PKA makes it a reliable tool for this purpose. |
| ln Vivo |
Kemptide is not typically used for in vivo studies; its primary application is as a biochemical tool for in vitro experiments. However, it has been reported that Kemptide is phosphorylated and activated after microinjection into Xenopus oocytes, demonstrating its utility as a substrate in living cells. This application allows researchers to study PKA activity in a cellular context, albeit in a specialized model system.
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| Enzyme Assay |
In a cell-free enzyme assay, Kemptide is used as a substrate to measure PKA activity. A typical protocol involves preparing a reaction mixture containing a buffer (e.g., Tris-HCl, pH 7.4), magnesium chloride, ATP (with or without a radioactive label), the PKA enzyme (or a sample containing PKA), and Kemptide. The reaction is initiated by adding ATP and incubated at 30°C for a set time. The reaction is then stopped, and the phosphorylated peptide is separated from the free ATP, often by spotting the mixture onto a phosphocellulose paper disk, which binds the positively charged peptide. The amount of incorporated radioactivity is then measured by scintillation counting.
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| Cell Assay |
Kemptide is used in cell-based assays to measure PKA activity in cell lysates or to study PKA-mediated phosphorylation events. In a typical protocol, cells are stimulated with a compound that modulates cAMP levels (e.g., forskolin, which activates adenylyl cyclase) or a PKA inhibitor. The cells are then lysed, and the lysate is used in an in vitro kinase assay with Kemptide as the substrate. This allows researchers to assess the activity of PKA in response to various treatments. Kemptide can also be microinjected into cells, such as Xenopus oocytes, to study its phosphorylation in vivo.
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| Animal Protocol |
Kemptide is not used for in vivo studies in animals. It is a research tool peptide and is not a therapeutic agent. Therefore, there are no standard in vivo animal experimental protocols for this compound. Its use is confined to in vitro biochemical and cell-based assays, where its specific phosphorylation by PKA makes it an invaluable tool for studying this critical signaling pathway.
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| ADME/Pharmacokinetics |
Kemptide is a peptide with a molecular weight of 771.91. It has a molecular formula of C32H61N13O9. As a peptide, it is typically handled and stored as a lyophilized powder, which is reconstituted in a suitable buffer (e.g., water or a mild buffer) before use. Its stability is generally good when stored dry at -20°C. Its role is not as a drug but as a research reagent.
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| Toxicity/Toxicokinetics |
Kemptide is a research reagent and is not considered a drug for therapeutic use; therefore, its toxicity is not a primary concern. At the concentrations used in biochemical assays (typically in the micromolar range), it is not toxic. It is handled as a standard laboratory chemical, and appropriate safety precautions (e.g., wearing gloves and lab coats) are recommended to avoid any potential, albeit low, risk.
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| References |
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| Additional Infomation |
Heptapeptide is used as a substrate for cAMP-dependent protein kinase.
Kemptide, with the sequence LRRASLG, is a synthetic peptide substrate for protein kinase A (PKA). It is one of the most widely used tools for measuring PKA activity in vitro due to its high specificity and predictable kinetics. It corresponds to a sequence from pig liver pyruvate kinase and is available as a high-purity peptide for research purposes. It is not a drug and has no clinical applications, but it is essential for studying cAMP-dependent signaling pathways. |
| Molecular Formula |
C32H61N13O9
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|---|---|
| Molecular Weight |
771.92
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| Exact Mass |
771.471
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| CAS # |
65189-71-1
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| Related CAS # |
Kemptide, 5-FAM labeled;1161072-61-2
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| PubChem CID |
9962276
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| Appearance |
White to off-white solid powder
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| Density |
1.4±0.1 g/cm3
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| Index of Refraction |
1.626
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| LogP |
-1.39
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| Hydrogen Bond Donor Count |
13
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| Hydrogen Bond Acceptor Count |
12
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| Rotatable Bond Count |
26
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| Heavy Atom Count |
54
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| Complexity |
1320
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| Defined Atom Stereocenter Count |
6
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| SMILES |
C[C@@H](C(=O)N[C@@H](CO)C(=O)N[C@@H](CC(C)C)C(=O)NCC(=O)O)NC(=O)[C@H](CCCN=C(N)N)NC(=O)[C@H](CCCN=C(N)N)NC(=O)[C@H](CC(C)C)N
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| InChi Key |
WIGDGIGALMYEBW-LLINQDLYSA-N
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| InChi Code |
InChI=1S/C32H61N13O9/c1-16(2)12-19(33)26(50)42-21(9-7-11-39-32(36)37)29(53)43-20(8-6-10-38-31(34)35)28(52)41-18(5)25(49)45-23(15-46)30(54)44-22(13-17(3)4)27(51)40-14-24(47)48/h16-23,46H,6-15,33H2,1-5H3,(H,40,51)(H,41,52)(H,42,50)(H,43,53)(H,44,54)(H,45,49)(H,47,48)(H4,34,35,38)(H4,36,37,39)/t18-,19-,20-,21-,22-,23-/m0/s1
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| Chemical Name |
2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-amino-4-methylpentanoyl]amino]-5-(diaminomethylideneamino)pentanoyl]amino]-5-(diaminomethylideneamino)pentanoyl]amino]propanoyl]amino]-3-hydroxypropanoyl]amino]-4-methylpentanoyl]amino]acetic acid
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| Synonyms |
Leu-arg-arg-ala-ser-leu-gly; Kemptide
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| HS Tariff Code |
2934.99.9001
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| Storage |
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment, avoid exposure to moisture. |
| Shipping Condition |
Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)
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| Solubility (In Vitro) |
H2O : ~50 mg/mL (~64.77 mM)
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| Solubility (In Vivo) |
Solubility in Formulation 1: 100 mg/mL (129.55 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.
(Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 1.2955 mL | 6.4774 mL | 12.9547 mL | |
| 5 mM | 0.2591 mL | 1.2955 mL | 2.5909 mL | |
| 10 mM | 0.1295 mL | 0.6477 mL | 1.2955 mL |
*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
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