PDKtide

Product Name: PDKtide

Sequence One Letter Code: KTFCGTPEYLAPEVRREPRILSEEEQEMFRDFDYIADWC

Sequence Three Letter Code: H-Lys-Thr-Phe-Cys-Gly-Thr-Pro-Glu-Tyr-Leu-Ala-Pro-Glu-Val-Arg-Arg-Glu-Pro-Arg-Ile-Leu-Ser-Glu-Glu-Glu-Gln-Glu-Met-Phe-Arg-Asp-Phe-Asp-Tyr-Ile-Ala-Asp-Trp-Cys-OH

Chemical Formula:C212H314N54O66S3

Molecular Weight: 4771.6

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: peptide substrate

Conjugation: Unconjugated

Code Nacres: NA.26

Application: PDKtide is a synthetic peptide substrate for phosphatidylinositide-dependent kinase 1 (PDK1), a central regulator of AGC family kinases, including AKT, S6K, and PKC isoforms. PDK1 plays a pivotal role in cell growth, metabolism, and survival through the PI3K signaling pathway. PDKtide is commonly used in in vitro kinase assays to quantify PDK1 activity, determine phosphorylation kinetics, and evaluate small-molecule inhibitors. It supports mechanistic studies of kinase activation and substrate recognition. This peptide is widely applied in research on metabolic regulation, oncogenic signaling, and therapeutic targeting of PI3K/AKT pathway dysregulation.

Current Research: Cellular growth, metabolism, and survival are regulated by intricate signaling networks that coordinate responses to environmental and intracellular cues. Among these pathways, the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway plays a central role in controlling cell proliferation, nutrient sensing, and survival mechanisms. A key regulator within this pathway is phosphatidylinositide-dependent kinase 1 (PDK1), a serine/threonine kinase responsible for activating multiple downstream members of the AGC kinase family. To study the catalytic activity and regulatory mechanisms of this kinase, researchers frequently use PDKtide, a synthetic peptide substrate specifically designed for monitoring PDK1 activity in biochemical assays. PDK1 and the PI3K Signaling Pathway PDK1 is a master regulator of a subset of kinases belonging to the AGC kinase family, which includes important signaling proteins such as AKT (protein kinase B), ribosomal S6 kinase (S6K), and several isoforms of protein kinase C (PKC). These kinases regulate essential cellular processes including protein synthesis, metabolism, cell survival, and cytoskeletal dynamics. Activation of PDK1 occurs downstream of PI3K signaling, which is triggered by growth factors, hormones, and other extracellular stimuli. When PI3K is activated, it produces phosphoinositide lipids such as phosphatidylinositol (3,4,5)-trisphosphate (PIP3) at the plasma membrane. These lipids recruit PDK1 and its substrates to the membrane through pleckstrin homology (PH) domains, enabling phosphorylation events that activate downstream kinases. One of the best-known targets of PDK1 is AKT, which becomes activated when PDK1 phosphorylates it at the activation loop residue. Activated AKT then regulates numerous downstream pathways that control glucose metabolism, protein synthesis, and cell survival. Because of these functions, dysregulation of the PI3K/AKT pathway is frequently associated with cancer, metabolic disorders, and other diseases. PDKtide as a Synthetic Kinase Substrate To analyze PDK1 activity in experimental systems, researchers require reliable substrates that can be efficiently phosphorylated by the kinase. PDKtide is a synthetic peptide designed to mimic a consensus phosphorylation sequence recognized by PDK1. The peptide provides a simplified and well-defined substrate that allows researchers to measure kinase activity in controlled biochemical environments. In in vitro kinase assays, purified PDK1 transfers a phosphate group from ATP to the target residue within the peptide. The extent of phosphorylation can then be quantified using several detection methods, including radioactive labeling, phospho-specific antibodies, or mass spectrometry. Because the peptide sequence is optimized for PDK1 recognition, it produces robust and reproducible signals in kinase assays. Measuring Kinase Activity and Phosphorylation Kinetics One of the primary applications of PDKtide is the quantitative measurement of PDK1 catalytic activity. By monitoring phosphorylation of the peptide over time, researchers can determine kinetic parameters such as reaction velocity, substrate affinity, and catalytic efficiency. These measurements provide insight into how PDK1 recognizes its substrates and how environmental factors—such as cofactors, lipid interactions, or protein partners—affect kinase activity. Such studies are essential for understanding how PDK1 integrates signals from upstream pathways and transmits them to downstream effectors. Evaluating Small-Molecule Kinase Inhibitors Because the PI3K/AKT pathway is frequently dysregulated in cancer and metabolic disease, PDK1 has become a target of interest for therapeutic drug development. Small-molecule inhibitors designed to block PDK1 activity may suppress oncogenic signaling and restore normal cellular regulation. PDKtide-based assays are widely used in screening and characterization of kinase inhibitors. In these experiments, candidate compounds are incubated with PDK1 before the peptide substrate is added. If the compound effectively inhibits the kinase, phosphorylation of PDKtide decreases. By comparing phosphorylation levels across different inhibitor concentrations, researchers can determine inhibitor potency and mechanism of action. This approach provides a convenient and reproducible platform for identifying compounds that modulate kinase activity and evaluating their potential as therapeutic agents. Investigating Kinase Activation and Substrate Recognition Beyond inhibitor screening, PDKtide supports mechanistic studies of kinase regulation. Researchers can use the peptide substrate to examine how structural changes in PDK1 influence its catalytic activity. For example, mutations within the kinase domain or regulatory regions can be evaluated by measuring their impact on peptide phosphorylation. These studies help clarify how PDK1 recognizes substrate sequences and how interactions with cofactors or regulatory proteins influence enzymatic function. Understanding these mechanisms contributes to a broader understanding of kinase signaling networks and phosphorylation-dependent regulation. Relevance to Cancer and Metabolic Research The PI3K/AKT signaling pathway is frequently altered in oncogenic transformation and tumor progression. Mutations in pathway components, including PI3K, PTEN, and AKT, can lead to constitutive activation of growth-promoting signals. Because PDK1 acts upstream of several AGC kinases, its activity can significantly influence these signaling cascades. In metabolic research, PDK1-dependent signaling pathways are also involved in insulin signaling, glucose metabolism, and cellular energy balance. Consequently, tools that allow precise measurement of PDK1 activity are valuable for understanding both cancer biology and metabolic disease mechanisms. A Versatile Tool for Kinase Research PDKtide provides a reliable and well-defined substrate for studying PDK1-mediated phosphorylation. Its use in kinase assays enables researchers to quantify enzymatic activity, analyze phosphorylation kinetics, and evaluate pharmacological inhibitors of the PI3K/AKT pathway. Because of its utility in biochemical assays and signaling studies, PDKtide has become an important reagent in research focused on cell signaling, metabolic regulation, and oncogenic pathway dysregulation. By supporting detailed analysis of PDK1 activity and substrate recognition, this peptide contributes to a deeper understanding of kinase signaling networks and their roles in human disease.