Threonine Phosphopeptide, PKC Substrate 4, phosphorylated

Product Name: Threonine Phosphopeptide, PKC Substrate 4, phosphorylated

Sequence One Letter Code: KR-pT-IRR

Sequence Three Letter Code: H-Lys-Arg-pThr-Ile-Arg-Arg-OH

Chemical Formula:C34H69N16O11P

Molecular Weight: 909

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: peptide substrate

Conjugation: Unconjugated

Code Nacres: NA.26

Application: Threonine Phosphopeptide, PKC Substrate 4 (phosphorylated) is a synthetic serine/threonine phosphopeptide developed as a defined substrate for protein kinase C (PKC)–related phosphatase research. Containing a phosphorylated threonine within a PKC consensus recognition motif, this peptide is specifically designed for monitoring dephosphorylation reactions in vitro. It enables precise quantification of serine/threonine phosphatase activity and supports kinetic characterization, enzyme specificity profiling, and inhibitor evaluation. Frequently applied in phosphatase assays, signaling pathway analysis, and drug discovery workflows, this peptide provides a reliable tool for studying phosphorylation-dependent cellular regulation. Its defined sequence and phosphorylation site facilitate accurate assessment of phosphate removal in biochemical and enzymatic assay systems involving PKC-mediated signaling pathways.

Current Research: Reversible phosphorylation of serine and threonine residues remains a central regulatory mechanism in eukaryotic signal transduction. Protein kinase C (PKC) isoforms, together with serine/threonine phosphatases such as PP1, PP2A, PP2B (calcineurin), and PP2C, coordinate tightly controlled phosphorylation–dephosphorylation cycles that govern cell proliferation, apoptosis, differentiation, and immune responses. Defined phosphopeptide substrates containing PKC consensus motifs are increasingly used to dissect these regulatory networks with high specificity and quantitative precision. Threonine Phosphopeptide, PKC Substrate 4 (phosphorylated) is widely applied in biochemical assays designed to measure phosphatase-mediated dephosphorylation kinetics. In vitro systems utilizing purified phosphatases or cell lysates employ this peptide to quantify catalytic efficiency (k_cat/K_m), determine substrate preferences, and compare isoform-specific activity. Because the phosphorylation site is structurally defined within a PKC-recognized sequence context, the peptide enables controlled evaluation of threonine-selective dephosphorylation events without confounding secondary phosphorylation sites. This is particularly valuable in distinguishing phosphatase activity toward PKC-generated phosphothreonine motifs versus non-consensus substrates. Recent research emphasizes the importance of serine/threonine phosphatase dysregulation in cancer, neurodegeneration, metabolic disease, and inflammatory disorders. For example, altered PP2A activity has been implicated in oncogenic signaling and tau hyperphosphorylation, while calcineurin signaling plays a critical role in T cell activation and cardiac hypertrophy. Defined phosphopeptide substrates are routinely incorporated into high-throughput screening platforms to identify small-molecule phosphatase modulators. The PKC Substrate 4 phosphopeptide supports inhibitor profiling studies, including evaluation of selective PP2A activators, calcineurin inhibitors, and novel phosphatase-targeted therapeutics. In addition to inhibitor discovery, this peptide is used in mechanistic studies examining crosstalk between PKC and downstream phosphatases. PKC-dependent phosphorylation events often serve as transient signaling switches that must be rapidly reversed to terminate signal propagation. Time-resolved dephosphorylation assays employing synthetic phosphothreonine peptides allow researchers to model signal decay kinetics under defined biochemical conditions. These studies contribute to quantitative understanding of signaling amplitude, duration, and feedback regulation in pathways such as MAPK activation, NF-κB signaling, and cytoskeletal remodeling. Phosphatase assay development also increasingly relies on standardized peptide substrates for assay validation and cross-platform comparison. Whether used in colorimetric phosphate-release assays, malachite green detection systems, HPLC-based separation, or mass spectrometry workflows, well-characterized phosphopeptides provide reproducible reference materials. The defined sequence of PKC Substrate 4 enables benchmarking of assay sensitivity, dynamic range, and enzyme selectivity in both manual and automated formats. Furthermore, systems biology approaches modeling signaling network dynamics require quantitative input parameters derived from well-controlled enzymatic measurements. Synthetic phosphothreonine peptides allow investigators to integrate biochemical rate constants into computational models of PKC-regulated pathways. Such models are increasingly applied to study aberrant signaling in tumor cells, immune activation, and stress-response pathways. Overall, current research underscores the importance of precisely defined phosphopeptide substrates in elucidating serine/threonine phosphatase regulation and PKC-dependent signaling control. Threonine Phosphopeptide, PKC Substrate 4 (phosphorylated) provides a reliable tool for kinetic analysis, inhibitor screening, assay development, and mechanistic investigation of phosphorylation-dependent cellular processes central to disease biology and therapeutic discovery.