Principle of the Assay: HPX ELISA kit applies the competitive enzyme immunoassay technique utilizing a monoclonal anti-HPX antibody and an HPX-HRP conjugate. The assay sample and buffer are incubated together with HPX-HRP conjugate in pre-coated plate for one hour. After the incubation period, the wells are decanted and washed five times. The wells are then incubated with a substrate for HRP enzyme. The product of the enzyme-substrate reaction forms a blue colored complex. Finally, a stop solution is added to stop the reaction, which will then turn the solution yellow. The intensity of color is measured spectrophotometrically at 450nm in a microplate reader. The intensity of the color is inversely proportional to the HPX concentration since HPX from samples and HPX-HRP conjugate compete for the anti-HPX antibody binding site. Since the number of sites is limited, as more sites are occupied by HPX from the sample, fewer sites are left to bind HPX-HRP conjugate. A standard curve is plotted relating the intensity of the color (O.D.) to the concentration of standards. The HPX concentration in each sample is interpolated from this standard curve.
NCBI and Uniprot Product Information
NCBI Description
This gene encodes a plasma glycoprotein that binds heme with high affinity. The encoded protein is an acute phase protein that transports heme from the plasma to the liver and may be involved in protecting cells from oxidative stress. [provided by RefSeq, Apr 2009]
Uniprot Description
HPX: Binds heme and transports it to the liver for breakdown and iron recovery, after which the free hemopexin returns to the circulation. Belongs to the hemopexin family.
Protein type: Secreted, signal peptide; Secreted
Chromosomal Location of Human Ortholog: 11p15.5-p15.4
Cellular Component: extracellular space; extracellular region
Molecular Function: protein binding; metal ion binding; heme transporter activity
Biological Process: receptor-mediated endocytosis; positive regulation of humoral immune response mediated by circulating immunoglobulin; positive regulation of tyrosine phosphorylation of Stat1 protein; heme transport; positive regulation of immunoglobulin production; viral reproduction; hemoglobin metabolic process; cellular iron ion homeostasis; heme metabolic process