- Created on the 1 February, 2017.
Osteopontin (OPN) which is also known as urinary stone protein, is a highly acidic calcium-binding glycosylated phosphoprotein that can be secreted by many cell types, such as kidney tubule cells, activated T cells, osteoblasts, vascular smooth muscle cells and macrophages. It has a molecular weight that can range from 66kDa to 44kDa depending on its phosphorylation and glycosylation states. It contains an Arg-Gly-Asp (RGD) amino acid sequence, this motif is also present in vitronectin, fibronectin and many extra cellular proteins which have the ability to bind members of the integrin family of cell surface receptors. It can be also present in a number of different molecular forms in vivo that can be due to phosphorylation, glycosylation, susceptibility to proteases, sulfation and differential RNA splicing.
Osteopontin is also susceptible to proteolytic fragmentation and there is suggestions that this process may have physiologic importance, for example, a study demonstrated that thrombin treatment can enhance OPN cell adhesive activity, implying that cleavage of OPN by thrombin can lead to exposing a cryptic adhesive sequence. We are highly recommend serum samples are not used for the measurement of OPN because of their limited stability.
Human osteopontin ELISA kit is a reliable quantitative method for measuring osteopontin (OPN) in human cell culture media, plasma and urine samples. This assay has a sensitivity detection limit of 3.33 ng/ml.
The minimum sensitivity detection limit of osteopontin (OPN) using this osteopontin ELISA kit was approximately 3.33 ng/ml. The dynamic assay range for this kit is 5.0 – 320.0 ng/ml.
- Phosphate is a specific signal for induction of osteopontin gene expression. Proc. Nat. Acad. Sci. (200) 97: 8352-8357. Beck, G. R.; Jr. Zerler, B. and Moran, E.
- Molecular cloning and sequencing of cDNA encoding urinary stone protein, which is identical to osteopontin. Biochem. Biophys. Res. Commun. (1992) 184: 859-864. Kohri, K., et al.
- Human bone sialoprotein: deduced protein sequence and chromosomal localization. J. Biol. Chem. (1990) 265: 2347-2351. Fisher, L. W.; McBride, O. W.; Termine, J. D. and Young, M. F.
- Full Name: Human Osteopontin ELISA Kit
- Reactivity: Human
- Sample Type: EDTA Plasma, Cell Culture Media, Urine
- Sensitivity: 3.33 ng/ml