Human Osteopontin

Secreted phosphoprotein 1 (SPP1) or osteopontin is a secreted cytokine. This phosphorylated acidic glycoprotein is expressed in various cells and tissues. It is synthesized by osteoblasts. The gene encoding SPP1 is localized on human chromosome 4q22.1.

Anti-Osteopontin antibody produced in rabbit has been used for ELISA.

A secreted, highly acidic, calcium binding, phosphorylated glycoprotein that is chemotactic for macrophages, smooth muscle cells, endothelial cells, and glial cells. In activated macrophages, OPN inhibits nitric oxide production and cytotoxicity. Human, mouse, rat, pig, and bovine OPN share 40% amino acid sequence identity. Secreted phosphoprotein 1 (SPP1) or osteopontin modulates inflammatory responses and glucose metabolism. It is a chemotactic factor and has a role in immune cell recruitment. The protein is also associated with cell growth, migration and differentiation. SPP1 attaches osteoclasts to the bone matrix. It is also involved in atherosclerotic process and bone mineralization. It is a marker of many cancers.

Lyophilized from a 0.2 μm filtered solution in phosphate buffered saline containing 2.5 mg bovine serum albumin.

Bioactivity Measured by the ability of the immobilized protein to support the adhesion of HEK293 human embryonic kidney cells. The ED50 for this effect is is 0.100-0.600 ug/mL.