Name: ProSpec Bio Recombinant Human p21 Activated Kinase 4
Brand: ProSpec Bio
SKU: PSB-PKA-259
Availability: InStock

<h2>What Are Kinases?</h2>
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Kinases are a structurally diverse class of enzymes that catalyze the transfer of the gamma-phosphate group of ATP to a hydroxyl group (Ser, Thr, Tyr) or amino group on a substrate, generating the phosphorylated product and ADP. In molecular biology, the most commonly used kinase is T4 Polynucleotide Kinase (T4 PNK), which phosphorylates 5'-hydroxyl termini of DNA and RNA for cloning, end-labeling, and library preparation. In cell biology and drug discovery, protein kinases (tyrosine kinases, serine/threonine kinases, dual-specificity kinases) are studied as targets for therapeutic inhibitors; over 500 protein kinase genes in the human genome (the 'kinome') regulate proliferation, apoptosis, differentiation, metabolism, and immune response. In molecular biology applications, choose T4 PNK for 5'-phosphorylation of DNA or RNA. In signaling research, choose recombinant protein kinase matched to your pathway target, and kinase inhibitors calibrated by published IC50 values.
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<h2 dir="ltr">What you will find:</h2>
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<ul>
<li>Active recombinant kinases for in vitro phosphorylation and enzyme activity assays.</li>
<li>Tyrosine kinase enzymes for oncology research, inhibitor screening, and drug discovery studies.</li>
<li>Serine/threonine kinase proteins for investigating signaling networks and metabolic pathway regulation.</li>
<li>Signaling and pathway-related enzymes for downstream functional validation and cell signaling research.</li>
<li>Research-grade kinase reagents for biochemical, cellular, and molecular biology workflows.</li>
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<h2>How to Choose Kinases</h2>
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T4 Polynucleotide Kinase (T4 PNK)
T4 PNK has two activities: a forward kinase activity that transfers the gamma-phosphate of ATP to 5'-OH termini of DNA or RNA (requires ATP, Mg2+), and a 3'-phosphatase activity that removes 3'-phosphate groups from RNA (requires ADP as phosphate acceptor). Use T4 PNK to phosphorylate synthetic oligonucleotides before blunt-end ligation, to radiolabel 5' termini with [gamma-32P]ATP for gel mobility assays, or to phosphorylate adaptor oligonucleotides in NGS library preparation. T4 PNK is inhibited by ammonium sulfate above 25 mM and phosphate buffers above 10 mM.
Protein kinases for signaling research
Recombinant protein kinases for in vitro kinase assays are available as the catalytic domain or full-length protein, expressed in insect cells (Sf9/Sf21), E. coli, or mammalian cells. Kinase activity is measured by phosphorylation of a defined peptide or protein substrate detected by radiolabeled ATP incorporation (32P filter binding, the gold standard), ADP-Glo luminescence assay, HTRF (homogeneous time-resolved FRET), or phospho-specific ELISA. For inhibitor screening (HTS), non-radioactive luminescent or FRET-based assays are used for safety and scalability.
Kinase inhibitors as pharmacological tools
Kinase inhibitors including staurosporine (broad-spectrum, IC50 in nM range for many kinases), wortmannin (PI3K inhibitor, IC50 ~5 nM), and selective inhibitors for EGFR, VEGFR, BRAF, CDK, and JAK families are used as research tools to dissect signaling pathways, validate drug targets, and study phosphorylation-dependent cellular processes. Always confirm the selectivity profile (kinome-wide IC50 panel) of an inhibitor before attributing cellular phenotypes to a single kinase target.
Kinase assay format
For biochemical kinase assays, match the assay format to the throughput and detection infrastructure available: radiometric 33P/32P assays for maximum sensitivity on low-activity kinases; ADP-Glo or HTRF for HTS on 96- or 384-well plates; mobility shift assays (LabChip) for direct detection of substrate phosphorylation shift without antibodies. For cellular kinase assays, phospho-specific antibodies, NanoBRET intracellular engagement assays, or live-cell kinase biosensors measure target engagement and downstream signaling.
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<h2>Specifications Context</h2>
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T4 PNK activity is expressed in units defined by the amount of enzyme transferring 1 nmol of phosphate from [gamma-32P]ATP to poly(dA) in 30 minutes at 37 degrees C. Typical reaction conditions use 1-10 units of T4 PNK per pmol of DNA ends in a 20-50 microliter reaction with 1 mM ATP and 1X T4 PNK buffer at 37 degrees C for 30 minutes. Protein kinase specific activity for recombinant kinase products is reported as picomoles of phosphate transferred per minute per microgram of enzyme under standardized substrate and ATP conditions. Chemoproteomics and activity-based protein profiling (ABPP) using desthiobiotin-ATP probes have become complementary approaches to traditional kinase inhibitor screening, enabling measurement of kinase engagement directly in cell lysates.&nbsp;
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<a href="https://mbpinc.net/contact-us">Contact the expert team</a> at MBP Inc. today and get high-quality kinases for advanced biochemical research workflows.

Kinases

ProSpec Bio

Key Specifications

ProSpec Bio Recombinant Human p21 Activated Kinase 4

Recombinant Human p21 Activated Kinase 4 by ProSpec Bio is recombinant human serine/threonine kinase (amino acids 1-591) produced in E. coli with a 37-amino-acid His tag at the N-terminus, a 628-amino-acid protein of 68.3 kDa that is more than 90% pure. It is supplied as a solution in 5 µg, 25 µg and 1 mg sizes for cell signaling research.