Srctide [GEEPLYWSFPAKKK-NH2]

Product Name: Srctide [GEEPLYWSFPAKKK-NH2]

Sequence One Letter Code: GEEPLYWSFPAKKK-NH2

Sequence Three Letter Code: H-Gly-Glu-Glu-Pro-Leu-Tyr-Trp-Ser-Phe-Pro-Ala-Lys-Lys-Lys-NH2

Chemical Formula:C81H119N19O20

Molecular Weight: 1679

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: Cancer Disease Research

Source / Species: Synthetic construct

Conjugation: Unconjugated

Code Nacres: NA.26

Application: Srctide is a well-established peptide substrate that can be phosphorylated by a broad range of protein kinases, including Src family kinases as well as several receptor tyrosine kinases and serine/threonine kinases. Due to its efficient phosphorylation and consistent performance, Srctide is widely used in biochemical kinase assays to measure enzyme activity and catalytic efficiency. The peptide provides a convenient platform for evaluating substrate specificity, comparing kinase activity across different enzymes, and assessing the potency of kinase inhibitors in drug discovery research. Its versatility has made it a commonly adopted substrate in signaling pathway studies, particularly those related to oncogenic kinase activation and receptor-mediated signal transduction. Srctide supports applications such as enzymatic assays, inhibitor screening, and mechanistic studies of kinase regulation, making it a useful tool for biochemical, pharmacological, and cancer research focused on kinase-driven cellular pathways.

Current Research: Protein phosphorylation is one of the most fundamental mechanisms regulating cellular signaling. Protein kinases transfer phosphate groups from ATP to specific amino acid residues on target proteins, thereby altering their activity, localization, or interactions. Among the many kinase families involved in signal transduction, Src family kinases (SFKs) play a particularly important role in controlling processes such as cell growth, adhesion, migration, and survival. Because abnormal kinase activation is frequently associated with cancer and other diseases, reliable tools for measuring kinase activity are essential in biochemical and pharmacological research. One widely used tool for this purpose is Srctide, a synthetic peptide substrate designed to support robust phosphorylation in kinase assays. Protein Kinases and Cellular Signaling Protein kinases regulate signaling pathways by catalyzing reversible phosphorylation of proteins, typically on serine, threonine, or tyrosine residues. This modification can activate enzymes, create docking sites for protein interactions, or trigger conformational changes that propagate signaling cascades. Kinases therefore function as central nodes in pathways that control cellular responses to extracellular signals. Among these enzymes, Src family kinases are non-receptor tyrosine kinases involved in numerous signaling pathways. Members of this family—including Src, Fyn, Yes, and Lyn—participate in processes such as receptor signaling, cytoskeletal organization, and cell cycle regulation. Because SFKs influence pathways that regulate proliferation and survival, their dysregulation has been implicated in tumor progression, metastasis, and therapeutic resistance. Studying the activity of Src and related kinases requires substrates that can be efficiently phosphorylated and reliably detected in biochemical assays. Srctide as a Synthetic Kinase Substrate Srctide is a synthetic peptide designed to serve as a convenient and efficient phosphorylation substrate for kinases. The peptide contains a sequence that can be readily recognized by several kinases, particularly Src family kinases, allowing it to undergo rapid phosphorylation in enzymatic reactions. Unlike full-length protein substrates, short peptides such as Srctide provide a simplified and controlled system for measuring kinase activity. Because the peptide contains a defined phosphorylation site, the extent of phosphorylation can be quantified using a variety of detection methods, including radioactive labeling, phospho-specific antibodies, fluorescence-based assays, or mass spectrometry. The robust phosphorylation efficiency of Srctide has made it a popular reagent for in vitro kinase assays, where researchers need reproducible and quantitative measurements of enzymatic activity. Broad Kinase Compatibility Although originally designed for Src kinase studies, Srctide can be phosphorylated by multiple classes of protein kinases, including some receptor tyrosine kinases and certain serine/threonine kinases. This broad compatibility allows the peptide to function as a general substrate for evaluating kinase activity across different enzymes. Because of this versatility, Srctide is often used when researchers wish to compare catalytic activity between different kinases or evaluate how mutations or regulatory factors influence enzymatic function. The ability to use the same substrate across multiple assays simplifies experimental design and facilitates cross-comparison of results. Applications in Kinase Activity Assays The primary use of Srctide is in biochemical kinase assays designed to quantify enzyme activity. In a typical experiment, purified kinase is incubated with Srctide and ATP under controlled conditions. As the kinase transfers a phosphate group to the peptide, the reaction can be monitored by measuring the formation of phosphorylated Srctide. These assays allow researchers to determine key kinetic parameters such as reaction rate, substrate affinity, and catalytic efficiency. Such measurements are essential for understanding how kinases function and how their activity is regulated by interacting proteins or cellular signals. Because peptide substrates are small and easily synthesized, Srctide-based assays are well suited for high-throughput experimental formats, such as microplate-based screening systems. Screening Kinase Inhibitors Protein kinases are major targets in modern drug discovery, particularly in cancer therapeutics. Many oncogenic pathways involve aberrant activation of kinases, and inhibitors that block these enzymes can suppress tumor growth. Srctide is frequently used in inhibitor screening assays. In these experiments, candidate compounds are incubated with a kinase before the peptide substrate is added. If a compound inhibits the kinase, phosphorylation of Srctide decreases, producing a measurable reduction in signal. By testing multiple concentrations of inhibitors, researchers can determine dose–response relationships and inhibitory potency. This approach is widely used in early-stage drug discovery to identify compounds that modulate kinase activity. Investigating Kinase Regulation and Signal Transduction Beyond inhibitor screening, Srctide also supports mechanistic studies of kinase regulation. Researchers can use the peptide substrate to examine how mutations, cofactors, or regulatory proteins influence kinase catalytic activity. Because Src family kinases participate in many signaling pathways, Srctide-based assays are often used to explore receptor-mediated signal transduction and oncogenic kinase activation. These studies help clarify how kinase networks transmit signals from cell surface receptors to intracellular targets. A Widely Used Tool for Kinase Research Thanks to its reliable phosphorylation properties and broad compatibility with multiple kinases, Srctide has become a commonly adopted substrate in kinase research. The peptide enables quantitative measurement of kinase activity, facilitates comparison of catalytic properties across enzymes, and supports screening of pharmacological inhibitors. As a result, Srctide is widely used in biochemical assays, drug discovery programs, and studies of signaling pathways associated with cancer and cellular regulation. Its versatility and consistent performance continue to make it an important tool for investigating kinase-driven cellular processes and developing therapeutic strategies targeting dysregulated signaling networks.