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Our scientists can help you choose the right assay format, substrate, and enzyme for your experiment.
About CAMK4
CAMK4 (Calcium/Calmodulin-Dependent Protein Kinase IV) belongs to the CAMK1 family of serine/threonine kinases and functions as a critical nuclear effector of calcium signaling. Upon intracellular calcium elevation, calmodulin binds and partially activates CAMK4, with full activation requiring phosphorylation by upstream kinases CaMKK1 or CaMKK2. Key substrates include CREB (Ser133), MEF2 transcription factors, HDAC4/5, and DARPP-32, linking CAMK4 to transcriptional regulation, synaptic plasticity, and chromatin remodeling. CAMK4 is predominantly expressed in neurons, T lymphocytes, and testes, placing it at the intersection of neurological function and immune regulation. Dysregulation of CAMK4 is implicated in systemic lupus erythematosus (SLE), multiple sclerosis, autoimmune nephritis, Alzheimer's disease, and various cancers including hepatocellular carcinoma. Its selective nuclear localization and distinct substrate profile from the cytoplasmic CAMK1/2 isoforms make CAMK4 an attractive therapeutic target for autoimmune diseases and neurodegeneration, with growing interest in isoform-selective inhibitor development.
Why PhosphoSens for CAMK4?
CAMK4 presents several assay challenges: it requires co-activation by calmodulin and calcium, making endpoint assays that consume ATP problematic, and its low basal activity means signal-to-noise is critical. ADP-Glo and HTRF endpoint formats miss the kinetic complexity of calmodulin-dependent activation and can produce artifacts when calmodulin or calcium concentrations are varied across compound screens. Radiometric assays offer sensitivity but are incompatible with real-time mechanistic studies. AssayQuant's PhosphoSens technology uses a chelation-enhanced fluorescent (CHEF) peptide substrate to continuously monitor CAMK4 phosphorylation in real time under physiological ATP concentrations (Km ATP). This enables accurate Ki and kinact/KI determination for covalent inhibitors, captures full progress curves across calmodulin titrations, and eliminates endpoint selection bias — providing richer kinetic data at higher throughput without radioactivity.
Key Pathways:
Calcium/Calmodulin Signaling
CREB Transcriptional Activation
T Cell Receptor Signaling
Synaptic Plasticity and LTP
Talk to a Scientist
Have questions about CAMK4 assay design, selectivity panels, or covalent inhibitor characterization?
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How pricing works:
Select a kit or substrate below, then request a quote. Bundle discounts apply automatically.
Select a kit or substrate below, then request a quote. Bundle discounts apply automatically.
Real-Time CAMK4 Activity Assays
Continuous, real-time fluorescent assays optimized for quantitative CAMK4 activity measurements, IC50 determination, and mechanistic studies.
Assay Format: Continuous kinetic fluorescence (real-time)
PhosphoSens-Kinetic assays directly quantify enzyme activity by continuously monitoring substrate phosphorylation or dephosphorylation in real time, generating a full progress curve in every well.
Learn more about PhosphoSens-Kinetic →Need pricing or availability? Select a kit or substrate to request a quote below.
Kits
PhosphoSens-Kinetic Kinase Activity Kit - AQT0426
Ready-to-use assay kits containing substrate and all essential reagents.
Kit Contents
- Optimized PhosphoSens® substrate (AQT0426)
- ATP, DTT, EGTA, Reaction Buffer & Dilution Buffer
Automatically save 10% when bundling 10ug recombinant enzyme with your 1,000 assay kit. View enzymes
Price: $425
Substrate
PhosphoSens Kinase Substrate AQT0426
Bulk PhosphoSens® substrate for assay development and high-throughput workflows.
Specifications
Automatically save 10% when bundling Reagent Packs with your substrate. View Reagent Packs
Price: $2795
Ready to request pricing for CAMK4?
Select a kit, substrate, or enzyme above. Our team will confirm pricing, availability, and any applicable bundle discounts.
Request a QuoteTRF CAMK4 Screening Assays
Robust endpoint TRF assays optimized for high-throughput screening and quantitative CAMK4 activity measurement in plate-based workflows.
Assay Format: Time-resolved fluorescence (TRF, endpoint)
PhosphoSens-Red assays use europium-based time-resolved fluorescence detection to enable robust, plate-based quantification of enzyme activity, making them well suited for high-throughput screening workflows.
Learn more about PhosphoSens-Red →Need pricing or availability? Select a kit or substrate to request a quote below.
Kits
PhosphoSens-Red Kinase Activity Kit - AQT0420
Ready-to-use TRF assay kits containing substrate and essential reagents.
Kit Contents
- Optimized PhosphoSens® substrate (AQT0420)
- ATP, DTT, EGTA, Reaction Buffer & Dilution Buffer
- Europium Detection Solution
Automatically save 10% when bundling 10ug recombinant enzyme with your 1,000 assay kit. View enzymes
Price: $455
Substrate
PhosphoSens Kinase Substrate AQT0420
Bulk substrate for PhosphoSens-Red TRF assays and high-throughput workflows.
Specifications
Automatically save 10% when bundling Reagent Packs with your substrate. View Reagent Packs
Price: $2795
Ready to request pricing for CAMK4?
Select a kit, substrate, or enzyme above. Our team will confirm pricing, availability, and any applicable bundle discounts.
Request a QuoteActive Recombinant Enzymes for CAMK4
Wild-type and mutant forms of CAMK4 for assay development, kinase profiling, and mechanistic studies. Enzymes are supplied active and optimized for PhosphoSens® substrates.
CAMK4, Active Full Length
Human • Baculovirus-Insect Cells
Technical Specifications
- Catalog: AQT-C15-10G
- Mutation: Full Length
- Species: Human
- Expression System: Baculovirus-Insect Cells
- Storage Buffer: Supplied as sterile 50 mM Tris-HCl, pH 7.5, 50-300mM NaCl, 10mM glutathione, 0.1mM EDTA, 0.25-1.0mM DTT, 0-0.1mM PMSF, 10-25% glycerol
- Molecular Weight: ~79 kDa
- Purity/Activity: For specific information on a given lot, see related technical data sheet.
- Storage Conditions: Store product at -70°C. For optimal storage, aliquot target into smaller quantities after centrifugation and store at recommended temperature. For most favorable performance, avoid repeated handling and multiple freeze/thaw cycles.
Available Sizes:
Price: $$348.00
Request a QuoteFrequently Asked Questions: CAMK4 Assays
How does PhosphoSens handle CAMK4 calmodulin-dependent activation in a continuous assay format?
PhosphoSens CSox-based peptide substrates are compatible with calcium and calmodulin in the assay buffer, allowing researchers to pre-activate CAMK4 with CaM prior to or simultaneously with substrate addition. Because fluorescence is monitored continuously, the onset of kinase activity is captured in real time, enabling precise measurement of activation kinetics and calmodulin concentration-response relationships without the endpoint selection artifacts that confound ADP-Glo or HTRF formats.
Can the PhosphoSens assay be used to profile covalent or irreversible CAMK4 inhibitors?
Yes. The continuous progress-curve format is uniquely suited for determining kinact and KI for covalent inhibitors, as the time-dependent loss of CAMK4 activity is directly observable in the fluorescence trace. This avoids the significant underestimation of covalent potency that occurs with fixed-time endpoint assays, providing more accurate structure-activity relationships for irreversible inhibitor campaigns.
What peptide substrate does AssayQuant recommend for CAMK4 assays?
AssayQuant offers PhosphoSens substrates optimized for the CAMK family, designed around consensus sequences derived from validated CAMK4 substrates such as CREB Ser133. The CSox-based fluorescent reporter is incorporated adjacent to the phosphorylation site so that phosphorylation by CAMK4 produces an immediate, real-time fluorescence increase, enabling Z-factor values suitable for HTS applications at physiological ATP concentrations.
Data & Resources
Explore data and documents to support your kinase and phosphatase experiments. Download sample data, protocols and other resources to see how our assays perform and to help you get started in your own lab. All validation data generated using PhosphoSens® assays under recommended conditions.
Sample Report: AQT0734 - EGFR Assay Validation Report
Each validation report provides experimental conditions and data showing:
- Enzyme titration and linearity
- Sensor peptide substrate titration and Km determination
- ATP titration and Km determination
- DMSO titration and assay tolerance
- Inhibitor titration and IC50 determination
Protocol
Inhibitor IC50 Protocol
See how the PhosphoSens-Kinetic Assay can be used to find the IC50 of a kinase inhibitor.
Download Protocol →Webinar
Webinar: Continuous Assay Validation
Discover how continuous assay formats power deep understanding of kinase function. See how PhosphoSens® assays guide inhibitor profiling, selectivity assessment, and mechanistic characterization.
Watch the Webinar →Service
KinSight™ CAMK4 Profiling
Need broader selectivity data? KinSight profiling runs your compounds across our full kinase panel under identical PhosphoSens conditions.
Learn about KinSight →Stay Informed
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