Glutathione Peroxidase 3 ELISA Kit (GPX3)

INTENDED USE

Human GPX3 ELISA kit can measure concentrations of GPX3 (glutathione peroxidase 3, GPX-P, GSHPx-3) present is plasma, serum, biological fluids or tissue homogenate samples.

INTRODUCTION

Glutathione peroxidase 3 (GPX3) is a soluble antioxidative selenoprotein enzyme that catalyzes hydrogen peroxide breakdown to water to limit accumulation of destructive reactive oxygen species. Ubiquitously expressed, cytosolic GPX1 and mitochondrial GPX4 represent other glutathione peroxidase homologs with broadly overlapping peroxide detoxification roles. By contrast GPX3 uniquely localizes to plasma and epithelial fluid lining spaces to provide frontline extracellular defense against oxidative damage across organs including the kidney, lung, intestine, breast, and reproductive tracts.

Though selenium supply and translational efficiency influence output, GPX3 transcription is characteristically induced by peroxides and other stress stimuli in a Nrf2-dependent manner. Beyond merely responding to oxidative threats, it helps maintain cellular redox homeostasis by modulating downstream regulators of antioxidant, anti-inflammatory, and prosurvival gene networks through NFκB, HuR, and other signaling intermediates. Loss of GPX3 sensitizes cells to oxidative injuries while compromising tissue integrity. Reconstituting glutathione peroxidase activity curtails acute kidney damage in select animal models, affirming the protective, nonredundant contributions of secreted GPX3.

Downregulated GPX3 associates with higher tumor grade and tissue selenium depletion across multiple cancer lineages—including smoking-induced lung cancers—and likely exacerbates disease by enabling unchecked oxidative DNA damage. Relatedly, GPX3-polymorphisms link with altered cancer susceptibility. Pharmacological GPX3 restoration could help strengthen antioxidant defenses. As extracellular selenium transfer remains poorly characterized, future work should address the mechanisms governing selenium bioavailability in GPX3 biogenesis and secretion. Advancing knowledge of compartmentalized redox control could profoundly shape GPX3-targeted interventions for preventative or therapeutic ends.

CONTENT

All reagents supplied need to be stored at 2 °C – 8 °C, unopened reagents will retain reactivity until expiration date. Do not use reagents beyond this date.

• One 96-Well Plate: Pre-coated with anti-GPX3 antibody.
• Standards: Lyophilized recombinant.
• Sample/Standard Dilution Buffer.
• Biotinylated-labelled Antibody.
• Antibody Dilution Buffer.
• HRP-Streptavidin Conjugate (SABC).
• SABC Dilution Buffer.
• TMB Substrate.
• Wash Buffer (25x).
• Plate Sealer.
• Product Instructions.

TYPICAL RESULTS

For this GPX3 ELISA kit, it is recommended that a standard curve is generated for each assay carried out.

Standard Curve: 0, 1.562, 3.125, 6.25, 12.5, 25, 50, 100 ng/ml.
Reactivity: Human
Sensitivity: 0.938 ng/ml
Range: 1.56 – 100 ng/ml
Principle: Sandwich, Double Antibody
Application: Research Use Only.

ASSAY CHARACTERISTICS

– Specificity: Highly specific for GPX3, no cross reactivity or interference between GPX3 and analogues was detected.
– Recovery: Serum (85 – 103%), EDTA Plasma (87 – 97%), Heparin Plasma (85 – 103%).
– Linearity: Serum (86 – 103%), EDTA Plasma (82 – 97%), Heparin Plasma (80 – 100%).
– Precison Intra-Assay: CV < 8%
– Precison Inter-Assay: CV < 10%

REFERENCES

1. Extracellular Glutathione Peroxidase GPx3 and Its Role in Cancer. Cancers (Basel). 2020 Aug 6;12(8):2197. Chang C., et al.
2. Proteomic landscape of the extracellular matrix in the fibrotic kidney. Kidney Int. (2023) 103 (6): 1063-1076. Li L., et al.
3. Preoperative plasma biomarkers associated with atrial fibrillation after coronary artery bypass surgery. J Thorac Cardiovasc Surg. (2021) 162 (3): 851-863.e3. Li X.Y., et al.
4. GPx3 dysregulation impacts adipose tissue insulin receptor expression and sensitivity. JCI Insight. (2020) 5 (11): e136283. Hauffe R., et al.

ADDITIONAL INFORMATION

• Full Name: Glutathione Peroxidase 3 ELISA Kit (GPX3)
• Reactivity: Human
• Sample Type: Plasma, Tissue Homogenates, Serum, Biological Fluids
• Sensitivity: 0.938 ng/ml

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