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| 5mg |
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| 10mg |
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| Targets |
PKI 14-22 amide, myristoylated specifically targets the catalytic subunit of cAMP-dependent protein kinase A (PKA). The peptide sequence is derived from the active region of the endogenous PKI protein (residues 14-22) and acts as a competitive inhibitor by binding to the substrate-binding site of the PKA catalytic subunit. The myristoylation (addition of a myristoyl group, C14:0 fatty acid) facilitates cellular uptake, allowing the peptide to reach its intracellular target. The compound exhibits high selectivity for PKA; at concentrations effective for PKA inhibition, it does not significantly affect other protein kinases. The Ki value is reported to be in the low nanomolar range.
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| ln Vitro |
In vitro, PKI 14-22 amide, myristoylated TFA functions as a potent PKA inhibitor. The compound reduces the IgG-mediated phagocytic response in immune cells and inhibits neutrophil adhesion, demonstrating its functional effects on cellular processes that are dependent on PKA activity. In kinase activity assays using purified PKA catalytic subunit and a standard substrate (e.g., Kemptide or a peptide substrate), the peptide inhibits PKA activity with an IC50 or Ki in the low nanomolar range. The myristoylated form is significantly more cell-permeable than the non-myristoylated version, making it suitable for intact cell studies.
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| ln Vivo |
In vivo, PKI 14-22 amide, myristoylated TFA has been shown to prevent the development of analgesic tolerance in mice, indicating that PKA plays a role in opioid tolerance mechanisms. The compound also inhibits protein translation and negative-strand RNA synthesis of Zika virus, suggesting potential antiviral applications. These results indicate that the myristoylated peptide can reach its intracellular targets in vivo when administered appropriately. The compound can be used in research fields such as opioid tolerance mechanisms and antiviral drug development.
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| Enzyme Assay |
A typical in vitro PKA kinase assay is performed using a radioactive or luminescent method. The reaction mixture (25 microL) contains kinase buffer (40 mM Tris-HCl, pH 7.4, 20 mM MgCl2, 0.1 mg/mL BSA), 50 microM ATP, 50 microM Kemptide substrate (Leu-Arg-Arg-Ala-Ser-Leu-Gly), and 1 ng of purified PKA catalytic subunit. PKI 14-22 amide, myristoylated TFA is added at varying concentrations (0.01-1000 nM). The reaction is initiated by the addition of the enzyme, incubated at 30degC for 15-30 minutes, and terminated by adding 0.5% phosphoric acid. An aliquot of the reaction mixture is spotted onto P81 phosphocellulose paper. The papers are washed 3 times in 0.75% phosphoric acid, dried, and the radioactivity (if using gamma-32P-ATP) is measured by liquid scintillation counting. Alternatively, a non-radioactive luminescent assay (e.g., ADP-Glo™) is used; the kinase reaction is performed, and the remaining ATP is converted to light by the detection reagent. The IC50 or Ki is calculated from the dose-response curve. For selectivity screening, the compound is tested against a panel of other protein kinases (e.g., PKC, CaMKII, AKT) at 1-10 microM.
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| Cell Assay |
For cell-based phagocytosis assays: RAW 264.7 macrophages or primary murine macrophages are seeded in 24-well plates (2×10⁵ cells/well) in DMEM + 10% FBS. After overnight incubation, cells are treated with PKI 14-22 amide, myristoylated TFA (0.1-10 microM) for 1-2 h at 37degC. For IgG-mediated phagocytosis, sheep red blood cells (SRBCs) are opsonized by incubation with subagglutinating amounts of rabbit anti-SRBC IgG for 30 min at 37degC. Opsonized SRBCs are added to the macrophages at a ratio of 20:1 (SRBC:macrophage) and incubated for 60 min at 37degC. Non-ingested SRBCs are removed by hypotonic lysis. The cells are fixed, stained with Giemsa or Diff-Quik, and the phagocytic index (number of ingested SRBCs per 200 macrophages) is calculated. For neutrophil adhesion assays: human neutrophils are isolated from healthy donors by Ficoll-Histopaque gradient centrifugation. Neutrophils are pre-incubated with PKI 14-22 amide, myristoylated TFA (0.1-10 microM) for 15 min at 37degC and then plated onto fibrinogen-coated wells (96-well plate, 5 microg/well). After 30 min, non-adherent cells are washed away, and adherent cells are quantified by measuring myeloperoxidase (MPO) activity or staining with crystal violet (absorbance at 595 nm). For viral studies: Vero cells or A549 cells are infected with Zika virus (MOI 0.1-1). The cells are treated with the peptide (1-20 microM) for 24-48 h. Viral RNA in the supernatant is quantified by qRT-PCR, and viral protein expression is assessed by Western blot using an anti-Zika virus antibody. Protein translation is measured using a puromycin incorporation assay.
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| Animal Protocol |
For the analgesic tolerance model: male ICR or C57BL/6 mice (25-30 g, n=8-10 per group) are used. Morphine tolerance is induced by subcutaneous (s.c.) injection of morphine (10 mg/kg) twice daily for 7 days. PKI 14-22 amide, myristoylated TFA is dissolved in sterile PBS or 5% DMSO/PBS. The compound is administered intrathecally (i.t., L5-L6 intervertebral space, 5 microL) or intraperitoneally (i.p., 0.5-5 mg/kg) 15 min before each morphine injection. The antinociceptive effect is measured by the tail-flick test or hot plate test (55degC, latency to lick the hind paw or jump) 30 min after morphine administration on days 1, 3, 5, and 7. Tolerance is defined as a significant reduction in the antinociceptive response over time. The peptide is expected to delay or prevent the development of morphine tolerance. For the Zika virus model: 6-8 week old A129 mice (IFN-alpha/beta receptor-deficient) or AG129 mice (IFN-alpha/beta/gamma receptor-deficient) are infected with Zika virus (10⁵ PFU, intraperitoneally). PKI 14-22 amide, myristoylated TFA (1-5 mg/kg) is administered intraperitoneally once daily for 5-7 days. Survival is monitored, and viral loads in blood, brain, and other tissues are quantified by plaque assay or qRT-PCR.
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| ADME/Pharmacokinetics |
The myristoylated peptide (molecular weight approximately 1323.51 g/mol for the TFA salt) is cell-permeable, which is a key advantage for intracellular targeting. However, as a peptide, its plasma half-life is expected to be very short (likely <30 minutes) due to rapid proteolytic degradation in serum. The myristoyl group improves cell penetration but does not significantly stabilize the peptide against degradation in plasma. For in vivo studies, multiple administrations or continuous infusion (e.g., via an osmotic pump) may be required to maintain effective concentrations. The TFA salt form ensures solubility in aqueous buffers. Detailed quantitative pharmacokinetic parameters (t½, AUC, Cmax, bioavailability) have not been published.
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| Toxicity/Toxicokinetics |
No formal toxicity data are available for PKI 14-22 amide, myristoylated TFA. In animal studies, the compound has been administered intrathecally (in mice) and intraperitoneally at doses up to 5 mg/kg without reported overt toxicity or mortality. The myristoyl group is a naturally occurring fatty acid and is generally considered biocompatible. At high concentrations, the peptide may cause non-specific membrane effects, but at the concentrations used for PKA inhibition (0.1-10 microM in vitro, 1-5 mg/kg in vivo), no significant adverse effects have been reported. Standard laboratory safety precautions (gloves, lab coat, eye protection) should be followed.
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| References | |
| Additional Infomation |
PKI 14-22 amide, myristoylated TFA is a research-grade peptide and is not approved for clinical use. It is a potent inhibitor of cAMP-dependent PKA that reduces the IgG-mediated phagocytic response and inhibits neutrophil adhesion. It can also prevent the development of analgesic tolerance in mice and inhibit Zika virus replication. The myristoyl group (C14:0) facilitates cell penetration, making this peptide significantly more effective in intact cell assays than the non-myristoylated version. The TFA salt is the standard commercial form. The compound should be stored as a powder at -20degC, protected from moisture. Reconstituted solutions should be aliquoted and stored at -80degC; avoid repeated freeze-thaw cycles.
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| Molecular Formula |
C55H101F3N20O14
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| Molecular Weight |
1323.51
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| Appearance |
White to off-white solid powder
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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 :~1.85 mg/mL (~1.40 mM)
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| Solubility (In Vivo) |
Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.
Injection Formulations
Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)(e.g. IP/IV/IM/SC) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). View More
Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] Oral Formulations
Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). View More
Oral Formulation 3: Dissolved in PEG400 (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 0.7556 mL | 3.7778 mL | 7.5557 mL | |
| 5 mM | 0.1511 mL | 0.7556 mL | 1.5111 mL | |
| 10 mM | 0.0756 mL | 0.3778 mL | 0.7556 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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