Casein Kinase 2 (CK2) Substrate alpha-subunit [RRRDDDSDDD]

Product Name: Casein Kinase 2 (CK2) Substrate alpha-subunit [RRRDDDSDDD]

Sequence One Letter Code: RRRDDDSDDD

Sequence Three Letter Code: H-Arg-Arg-Arg-Asp-Asp-Asp-Ser-Asp-Asp-Asp-OH

Chemical Formula:C45H73N19O24

Molecular Weight: 1264.3

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: peptide substrate

Conjugation: Unconjugated

Code Nacres: NA.26

Application: Casein Kinase 2 (CK2) Substrate α-Subunit (RRRDDDSDDD) is a synthetic peptide engineered for selective measurement of CK2 activity. The clustered acidic residues conform to the canonical CK2 consensus sequence, promoting efficient phosphorylation by the CK2 α-catalytic subunit. CK2 is a serine/threonine kinase capable of utilizing ATP or GTP and is sensitive to heparin inhibition. This substrate is widely used in kinase assays, kinetic studies, and inhibitor screening to support investigations into CK2-mediated regulation of cell growth, survival, and transcription.

Current Research: Casein Kinase 2 (CK2) Substrate α-Subunit (RRRDDDSDDD) is a synthetic peptide designed for selective and efficient measurement of CK2 serine/threonine kinase activity. The sequence contains a central serine residue flanked by clustered acidic amino acids, conforming to the canonical CK2 consensus motif (S/T-X-X-D/E or acidic-rich environments downstream of the phospho-acceptor site). This configuration promotes high catalytic efficiency by the CK2 α catalytic subunit. CK2 is a constitutively active, ubiquitously expressed serine/threonine kinase involved in regulating diverse cellular processes including proliferation, survival, transcription, and DNA repair. The α-subunit peptide substrate provides a standardized tool for biochemical characterization of CK2 activity. Structural and Functional Basis The peptide sequence: RRRDDDSDDD features: A single serine residue as the phosphorylation site Multiple downstream acidic residues (Asp) that enhance substrate recognition N-terminal basic residues (Arg) supporting solubility and assay compatibility CK2 uniquely tolerates both ATP and GTP as phosphate donors and is characteristically inhibited by heparin, distinguishing it from many other kinases. Applications in CK2 Research 1. Enzymatic Activity Assays This substrate is widely used in in vitro kinase assays employing recombinant CK2 α or holoenzyme complexes. Phosphorylation can be quantified via: Radiometric incorporation of γ-³²P Phospho-specific antibody detection Mass spectrometry analysis Coupled luminescent kinase assays 2. Kinetic Characterization The defined sequence supports determination of kinetic parameters such as Km and Vmax under controlled experimental conditions, facilitating mechanistic studies of CK2 catalytic behavior. 3. Inhibitor Screening The peptide is suitable for evaluating selective CK2 inhibitors. Reduced phosphorylation in the presence of candidate compounds enables calculation of IC₅₀ values and assessment of inhibitor potency. 4. Signaling Pathway Studies CK2 regulates numerous substrates involved in: Cell cycle progression Apoptosis suppression Transcription factor activation DNA damage response This substrate enables focused examination of CK2-mediated phosphorylation events in biochemical systems. Advantages Optimized CK2 consensus motif High specificity for CK2 catalytic activity Compatible with multiple detection platforms Suitable for high-throughput screening Reproducible and well-characterized sequence Experimental Considerations Assays should include appropriate divalent cations (e.g., Mg²⁺) and optimized ATP or GTP concentrations. Heparin can be used as a control inhibitor to confirm CK2 specificity. Substrate concentration should be selected relative to the enzyme’s Km to ensure accurate kinetic interpretation.