CDK1 Substrate [HATPPKKKRK]

Product Name: CDK1 Substrate [HATPPKKKRK]

Sequence One Letter Code: HATPPKKKRK

Sequence Three Letter Code: H-His-Ala-Thr-Pro-Pro-Lys-Lys-Lys-Arg-Lys-OH

Chemical Formula:C53H95N19O12

Molecular Weight: 1190.5

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: Cancer Disease Research

Conjugation: Unconjugated

Code Nacres: NA.26

Application: CDK1 Substrate [HATPPKKKRK] is a synthetic peptide encompassing a consensus phosphorylation motif recognized by cyclin-dependent kinase 1 (CDK1/CDC2). CDK1 is the principal driver of G2/M phase transition and mitotic entry, phosphorylating substrates involved in chromosome condensation and spindle assembly. This peptide serves as a defined in vitro substrate for kinase assays, enabling quantitative measurement of CDK1 catalytic activity through radiometric or fluorescence-based detection methods. It is particularly useful for enzyme kinetics studies, inhibitor profiling, and analysis of CDK1–cyclin B complex regulation. The sequence provides a reproducible platform for dissecting cell cycle control mechanisms and assessing pharmacological modulators targeting mitotic kinase activity.

Current Research: CDK1 Substrate [HATPPKKKRK] is a synthetic peptide incorporating a consensus phosphorylation motif recognized by cyclin-dependent kinase 1 (CDK1), also known as CDC2. CDK1 is the master regulatory kinase governing the G2/M phase transition and mitotic entry in eukaryotic cells. By providing a defined and minimal phosphorylation sequence, this peptide functions as a robust in vitro substrate for quantitative assessment of CDK1 catalytic activity in biochemical and cell cycle research applications. CDK1 and Mitotic Regulation CDK1 operates in complex with regulatory cyclins—most prominently cyclin B—to form the CDK1–cyclin B complex, also referred to as maturation-promoting factor (MPF). Activation of this complex triggers a phosphorylation cascade that drives key mitotic events, including: Chromosome condensation Nuclear envelope breakdown Mitotic spindle assembly Centrosome maturation CDK1 activity is tightly controlled by cyclin binding, activating phosphorylation at Thr161, and inhibitory phosphorylation at Thr14 and Tyr15. Dysregulation of CDK1 signaling is associated with uncontrolled proliferation, genomic instability, and oncogenesis, making it a significant target in cancer research and therapeutic development. Consensus Phosphorylation Motif The peptide sequence HATPPKKKRK contains a proline-directed serine/threonine motif characteristic of CDK1 substrates. CDK1 preferentially phosphorylates serine or threonine residues followed by a proline (S/T–P motif), often within basic residue–rich contexts that enhance substrate recognition. This defined sequence allows selective and reproducible phosphorylation by active CDK1–cyclin complexes under controlled assay conditions. Because the substrate is short and structurally defined, it minimizes secondary structural influences that can complicate interpretation in full-length protein substrates. This makes it particularly valuable for mechanistic enzymology studies. Applications in Kinase Assays CDK1 Substrate [HATPPKKKRK] is widely used in: Radiometric kinase assays using [γ-³²P] ATP incorporation Fluorescence-based phosphorylation detection assays Enzyme kinetic studies (K_m and V_max determination) Time-course analysis of catalytic activity Comparative activity profiling of wild-type and mutant CDK1 variants The peptide’s reproducibility supports high assay consistency, which is essential for quantitative enzymology and inhibitor characterization. Inhibitor Profiling and Drug Discovery Given CDK1’s pivotal role in mitosis, pharmacological inhibitors targeting CDK1 or broader CDK families are under investigation for anticancer therapy. This peptide substrate enables precise evaluation of inhibitor potency and selectivity in vitro. It is particularly useful for: Determining IC₅₀ values of candidate CDK inhibitors Structure–activity relationship (SAR) studies Assessing ATP-competitive versus allosteric inhibition Evaluating CDK1–cyclin B complex modulation Because the assay readout directly reflects phosphorylation of a defined sequence, inhibitor effects can be quantified without confounding regulatory inputs present in cellular systems. Mechanistic Studies of Cell Cycle Control Beyond drug discovery, this substrate supports investigation of CDK1 regulatory mechanisms. Researchers can assess how cyclin B binding, phosphorylation state, or regulatory proteins (e.g., Wee1, Cdc25 phosphatases) influence catalytic activity. It is also valuable for reconstitution studies examining mitotic kinase networks in vitro. The minimal peptide format provides a clean experimental platform for dissecting kinase–substrate interactions and catalytic efficiency under defined biochemical conditions. Experimental Advantages Consensus CDK1 recognition motif Reproducible and defined phosphorylation site Compatible with radiometric and fluorescence-based assays Suitable for kinetic analysis and inhibitor screening Supports mechanistic investigation of CDK1–cyclin B regulation Research Impact By enabling accurate and quantitative measurement of CDK1 activity, CDK1 Substrate [HATPPKKKRK] serves as a foundational tool in cell cycle research. Its utility spans basic studies of mitotic regulation to translational efforts aimed at developing CDK-targeted therapeutics. The defined sequence and reliable assay performance make it well suited for dissecting kinase signaling pathways central to cell proliferation and cancer biology.