Casein Kinase 2 Substrate Peptide - ≥98% , CAS No.132176-35-3

CAS: 132176-35-3 Cat. No.: C1426591 Formule: C₄₅H₇₃N₁₉O₂₄ Poids moléculaire: 1264.17

GRADE & PURITY ≥98%

Storage

Protected from light,Desiccated,Store at -80°C

Shipped In

Dry ice packs + Cold packs

Vue d’ensemble

Casein Kinase 2 Substrate Peptide is a common CK2 substrate peptide. Casein Kinase 2 Substrate Peptide is synthesized with its C-terminus conjugated to 5-[(2-aminoethyl)amino]naphthalene-1-sulfonic acid (EDANS). Casein Kinase 2 Substrate Peptide can be used for protein kinase CK2 activity determination.

Specifications

Spécifications et pureté

≥98%

Conditions de stockage de stockage

Protected from light,Desiccated,Store at -80°C

Expédié en

Dry ice packs + Cold packs

Ce produit nécessite l'expédition en chaîne froide. Les services terrestres et autres services économiques ne sont pas disponibles.

Pureté

≥98%

Noms et identifiants

Poids moléculaire

1264.17

Application Protocols

• Radiometric CK2 assay (general, literature):
  1. Prepare assay buffer (e.g., 25 mM Tris-HCl pH 7.5, 10 mM MgCl2, 1 mM DTT). 2) Mix peptide substrate (e.g., 10–100 µM), CK2 (1–10 nM), cold ATP (e.g., 50 µM) plus trace [γ-32P]ATP. 3) Incubate 10–30 min at 30°C. 4) Spot aliquots onto P81 phosphocellulose, wash with 0.5% phosphoric acid, dry, and count CPM. Include no-enzyme/no-ATP controls.
• ADP-Glo/luminescent assay (general):
  1. Assemble reactions with peptide (1–100 µM), CK2 (0.5–10 nM), ATP near its Km in compatible buffer. 2) Incubate 10–60 min at RT or 30°C. 3) Add detection reagents per kit instructions. 4) Read luminescence and convert to rates using ADP standards.
• LC–MS endpoint assay (general):
  1. React peptide with CK2/ATP/Mg2+ under defined conditions. 2) Quench with EDTA/formic acid. 3) Analyze by LC–MS to quantify +80 Da phosphorylated species; use extracted ion chromatograms to determine conversion.
• Notes:
  • Conditions above are typical literature ranges and must be optimized empirically for this specific lot and detection platform. No item-specific specifications are implied.

Biological Roles

• Context (general, literature):
  • Casein kinase 2 (CK2; CSNK2A1/CSNK2A2 catalytic subunits with regulatory CK2B) is a ubiquitous, constitutively active serine/threonine kinase that prefers acidic substrates. It phosphorylates hundreds of proteins involved in transcription, translation, DNA repair, circadian regulation, and cell signaling.
• Role of substrate peptides in research:
  • Defined peptide substrates allow isolation of the catalytic activity of CK2 from complex cellular contexts, enabling precise kinetic measurements (Km, kcat) and inhibitor profiling.
  • Peptide substrates matching the CK2 consensus (S/T followed by acidic residues) help map sequence determinants of recognition and can be engineered to tune turnover for specific assays.
• Selectivity considerations (general):
  • While designed for CK2, acidic substrate motifs can be phosphorylated by other acidophilic kinases under non-stringent conditions. Using purified CK2 or CK2-selective inhibitors/controls helps confirm specificity.
• Readouts enabled:
  • Quantitation of phosphorylation stoichiometry, Michaelis–Menten parameters, and inhibitor IC50/Ki values for CK2 using defined peptide concentrations and ATP titrations (literature).

Buffer Applications

This product is a peptide substrate rather than a buffering reagent; it is not used to set or control pH. However, appropriate buffer choice is critical for CK2 assays.

• Typical CK2 assay buffers (literature, example ranges):
  • 25–50 mM Tris-HCl, pH 7.5–8.0 or 25–50 mM HEPES, pH 7.0–7.5
  • 5–20 mM MgCl2 (required for ATP coordination)
  • 1–5 mM DTT (to maintain enzyme thiols)
  • 0.01–0.1% nonionic detergent (e.g., Tween-20) to reduce nonspecific adsorption (optional)
  • 0.1–1 mg/mL BSA as carrier/blocker when working at low peptide concentrations (optional; ensure no interference with detection chemistry)
• Additives to avoid (general):
  • High phosphate (can chelate Mg2+ and compete with ATP in certain detection formats), high EDTA/other chelators, and high concentrations of primary amines that may interfere with some detection reagents.
• Practical tips:
  • Adjust ionic strength (50–150 mM NaCl or KCl) to reduce nonspecific interactions without compromising CK2 activity.
  • For luminescent ADP detection kits, follow the vendor’s compatible buffer recommendations to avoid quenching.

Green Alternatives

• Environmental perspective (general):
  • As an aqueous-compatible peptide, the preferred solvent system is water-based buffers, which are greener than organic solvent-intensive systems.
• Greener assay formats (literature):
  • Replace radiometric assays with non-radioactive detection (e.g., luminescent ADP detection, mobility shift capillary electrophoresis, or LC–MS). These reduce radioactive waste and associated hazards while maintaining sensitivity.
  • Use minimal DMSO (<1–5%) when needed for dissolution; validate that enzyme performance is unaffected.
• Comparison of detection approaches (general):
  • Radiometric: highest sensitivity, but generates radioactive waste and requires specialized handling.
  • Luminescence/fluorescence: sensitive, no radioactivity; may have reagent waste and luminescent chemistry considerations.
  • Mass spectrometry: solvent usage can be optimized; enables multiplexing and specificity, with lower hazardous waste if using aqueous gradients.
• Operational green tips:
  • Prepare concentrated aqueous stocks to minimize solvent volume and shipping weight.
  • Aliquot to avoid repeated thawing and disposal of compromised material.
  • Choose phosphate-free, Good’s buffers to avoid metal chelation and to improve downstream waste compatibility.

Pharmaceutical Uses

• Formulation/excipient status: Not applicable. This product is supplied for research use only and is not intended for pharmaceutical formulation or as an excipient.
• R&D utility (non-clinical):
  • Useful in preclinical discovery workflows as a biochemical tool for profiling CK2 inhibitors, determining mechanism-of-action in vitro, and benchmarking assay performance across platforms (radiometric vs. luminescent vs. MS-based). No clinical or therapeutic use is claimed or supported.

Physical Properties

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight and formula: Not specified for this item; refer to CoA/Spec Sheet.
• Solubility (general guidance, literature):
  • Short, non-modified peptides of this class are typically readily soluble in aqueous buffers (pH 6–8). If hydrophobic residues are present, initial dissolution in a small volume of DMSO (≤10% v/v final) or addition of minimal NaOH can aid solubilization.
• pKa/logP (general):
  • Peptides possess multiple ionizable groups (N-terminus, C-terminus, side chains), rendering them overall hydrophilic with no meaningful logP in the small-molecule sense. Effective charge depends on sequence and pH (literature).
• Stability (general, literature):
  • Solid, lyophilized peptides are typically stable when kept dry, protected from light, and frozen. In solution, stability improves at neutral to slightly basic pH, at low temperature, and in the presence of carrier proteins only if compatible with the assay.
• Spectral features (general):
  • UV absorbance at 214 nm/220 nm arises from peptide bonds; 280 nm absorbance depends on presence of Trp/Tyr/Phe (literature). Exact extinction coefficient is sequence-dependent and not specified for this item.

Quality and Grades

• Grade/purity for this specific item: Not specified for this item; refer to CoA/Spec Sheet.
• What “research-use” implies:
  • Supplied for research and laboratory use only; not for human or veterinary use, clinical diagnostics, or food/cosmetic applications.
• Considerations for kinase substrate peptides (general):
  • Purity (HPLC area %) and identity (MS, optionally amino-acid analysis) are critical to minimize background signals and ensure reproducible kinetics. Trace truncations or deletions can alter phosphorylation rates.
  • Counter-ions (e.g., TFA vs acetate) and residual solvents/salts can influence solubility and enzyme compatibility. If the counter-ion matters, request the CoA.
  • Lyophilization excipients (if any) and salt form should be stated on the CoA; these impact accurate molarity calculations.
• Batch-to-batch consistency:
  • For quantitative enzyme kinetics, verify peptide content (% by weight) when calculating stock concentrations. Use CoA data (peptide content, water content) when available to correct for non-peptide mass.

Reaction and Applications

• Primary application: substrate for casein kinase 2 (CK2) activity assays and inhibitor screening (research use only).
• Use modes (literature):
  • Radiometric kinase assays with [γ-32P]ATP: peptide serves as acceptor; incorporation measured by scintillation counting or phosphorimaging after capture on P81/cellulose membranes.
  • Coupled ADP-detection assays (e.g., ADP-Glo, pyruvate kinase/lactate dehydrogenase): phosphorylation generates ADP proportional to activity.
  • LC–MS/MS endpoint assays: monitor mass shift (+80 Da per phosphate) of the peptide for substrate turnover and specificity.
  • Capillary electrophoresis or HPLC with UV/fluorescence if labeled variants are employed.
• Practical tips (general):
  • Optimize peptide concentration around the Km for the peptide (often 1–200 µM in literature) to balance sensitivity and linearity. Excess peptide can mask inhibitor potency; too little increases noise.
  • Maintain Mg2+ (5–20 mM) and ATP (typically 10–200 µM) within the linear range of the detection method. CK2 is active over a broad pH (≈6.5–8.5), commonly run near pH 7.5–8.0.
  • Include phosphatase inhibitors if cellular extracts are used. For purified CK2, include DTT (1–5 mM) to protect enzyme thiols.
  • Time-course assays help confirm initial-rate conditions (<15–20% substrate consumption).

Reaction Conditions

• CK2 phosphorylation assay (general literature guidance; adjust empirically):
  • Enzyme: recombinant CK2 holoenzyme or catalytic subunit; typical working range 0.5–50 nM depending on substrate turnover and detection method.
  • Substrate peptide: often 1–200 µM; bracket around expected Km to operate under initial-rate conditions.
  • ATP: 10–200 µM for inhibitor screening near Km(ATP); up to 1 mM for Vmax determination. Include 5–20 mM MgCl2.
  • Buffer: 25–50 mM Tris-HCl or HEPES, pH 7.0–8.0; 1–5 mM DTT; optional 0.01–0.1% Tween-20.
  • Temperature/time: 25–37°C; typical reaction times 5–60 min, ensuring <20% substrate consumption.
  • Quench/readout: EDTA (50–100 mM) or stop solutions per kit protocols; detect by radiometric capture, luminescent ADP detection, CE mobility shift, or LC–MS (+80 Da for phosphate per site).
• Controls:
  • No-enzyme and no-ATP blanks; known CK2 inhibitor as positive control for inhibition; heat-inactivated enzyme control for background.
• Data quality tips:
  • Verify linearity in time and enzyme concentration. Correct for DMSO content across wells. Include internal standards for MS-based methods.

Safety and Handling

• GHS/SDS data:
  • Signal word: Not specified for this item; refer to SDS.
  • Hazard statements, pictograms, classification: Not specified for this item; refer to SDS.
• General laboratory safety (good practice for peptides/biochemicals):
  • Handle in a clean environment to avoid contamination with proteases or moisture; use nitrile gloves, lab coat, and safety glasses.
  • Avoid inhalation of lyophilized powders; reconstitute in a fume hood or biosafety cabinet if dusting is possible.
• Incompatibilities (general):
  • Avoid strong oxidants and acids/bases during storage; avoid repeated freeze–thaw which can promote degradation and aggregation.
• First-aid overview (general, non-authoritative):
  • Skin/eye contact: Rinse with water for several minutes; remove contaminated clothing. Inhalation: move to fresh air. Ingestion: rinse mouth; seek medical attention. Always follow your institutional SDS and procedures.
• Special risks:
  • Peptides are not known peroxide-formers. The principal risks are low volatility particulate exposure and potential allergic sensitization upon chronic exposure; minimize aerosolization and follow standard biosafety practices.
• Definitive guidance: Defer to the product’s SDS and institutional EHS requirements for authoritative hazard, exposure controls, and disposal instructions.

Solvent Selection

• Polarity and miscibility (general):
  • CK2 substrate peptides are typically hydrophilic and dissolve in aqueous buffers (e.g., 10–50 mM Tris or HEPES, pH 7.0–8.0). For challenging sequences, co-solvents such as DMSO (≤10% v/v) or a brief pH adjustment can assist dissolution.
• Recommended dissolution workflow (general):
  • Start with cold, nuclease-/protease-free water or assay buffer. Add solvent gradually while gently vortexing. If undissolved, add minimal DMSO or small aliquots of 0.1–1 M NaOH until dissolved, then back-titrate to target pH.
• Buffer compatibility considerations (general):
  • CK2 assays commonly include Mg2+ and ATP; avoid phosphate buffers at high concentrations that can chelate metal ions or interfere with luminescent ATP/ADP detection kits. Use Tris, HEPES, or MOPS instead (literature).
• Comparison (general guidance):
  • Water/buffer: first choice for activity assays; preserves enzyme activity.
  • DMSO: useful as co-solvent; keep at the lowest percentage tolerated by CK2 and the assay readout.
  • Basic aqueous stock (slight): can help dissolve acidic peptides; neutralize after dilution into assay mixture.

Storage and Reconstitution

• Item-specific storage conditions (per Product Data):
  • Store at −80°C, desiccated, and protected from light.
  • Shipped on dry ice packs + cold packs.
• Reconstitution (general guidance for peptides):
  • Use sterile, nuclease-/protease-free water or assay buffer to prepare a concentrated stock solution. If solubility is limited, dissolve first in a minimal volume of DMSO (keep ≤10% v/v final) or adjust pH slightly, then dilute with buffer.
  • Filter-sterilize if needed (0.22 µm) and dispense into single-use aliquots to avoid repeated freeze–thaw.
  • Record the exact solvent, pH, and any counter-ion information from the CoA for accurate molarity calculations.
• Working solution stability (general):
  • Keep on ice during use; for multi-day use, store at 4°C and assess activity/appearance before reuse. For long-term storage, freeze aliquots at −80°C.
  • Avoid multiple freeze–thaw cycles; discard aliquots showing precipitation or loss of activity in assay controls.
• Light/moisture protection:
  • Maintain under low light and dry conditions; use desiccant in secondary containment for the lyophilized solid.
• Definitive, lot-specific guidance: Not specified for this item; refer to CoA/Spec Sheet.

Structure and Identity

• Item identity: Casein Kinase 2 Substrate Peptide (SKU: C1426591); CAS: 132176-35-3.
• Item-specific identifiers:
  • Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet.
  • InChIKey: Not specified for this item; refer to CoA/Spec Sheet.
  • PubChem CID: Not specified for this item; refer to CoA/Spec Sheet.
• Structural class (general, literature):
  • A short synthetic peptide designed to match the casein kinase 2 (CK2) phosphorylation consensus (Ser/Thr followed by acidic residues). Typical CK2 substrate peptides incorporate multiple acidic residues around the phosphorylation site to enhance CK2 recognition and turnover (literature).
• Functional features (general):
  • Contains at least one serine or threonine residue as the phosphorylation acceptor (literature).
  • Flanking sequence often enriched in Asp/Glu and sometimes basic residues to modulate solubility and assay performance (literature).
• 2D description in words (general):
  • Linear amino-acid chain with standard peptide backbone (repeating –NH–CHR–CO–), side chains arranged to present an S/T residue in a favorable acidic context for CK2-catalyzed phosphorylation (literature).

Synthetic Utility

This item is a finished peptide substrate rather than a synthetic building block for chemical transformations; it is typically not used as a precursor in organic synthesis. Nonetheless, it has utility in method development and analytical calibration.

• Utility in analytical/synthetic method contexts (general):
  • Serves as a defined standard for developing and validating kinase assay workflows, including optimization of ATP, Mg2+, and buffer conditions.
  • The phosphorylated product peptide can be prepared enzymatically and used as a calibration standard for LC–MS quantitation of phosphorylation stoichiometry.
  • Sequence variants (not provided here) are often synthesized via SPPS to probe structure–activity relationships for CK2 recognition (literature).
• Peptide chemistry notes (general):
  • If modifications or labels are introduced (e.g., fluorescent tags or biotin), coupling is typically performed on-resin via SPPS using orthogonal protecting groups; such modifications profoundly affect solubility and detection but are not specified for this item.

Target Specificity

Target specificity data such as antigen/epitope/clone/isotype is applicable to antibodies and affinity reagents, not to unlabeled peptide substrates. For this product, no target-binding specificity beyond being a phosphorylation substrate for CK2 is provided or applicable.