Recombinant Human OPN protein

Osteopontin (OPN), a multifunctional phosphorylated glycoprotein encoded by the *SPP1* gene, is a key extracellular matrix protein and cytokine involved in diverse physiological and pathological processes. Naturally expressed in tissues such as bone, kidney, and immune cells, OPN regulates cell adhesion, migration, immune responses, and tissue remodeling by interacting with integrins and CD44 receptors. Its roles in inflammation, cancer progression, and bone mineralization have made it a focal point in biomedical research.

Recombinant OPN production emerged to address limitations of native protein isolation, including low yield, batch variability, and contamination risks. Using genetic engineering, the *SPP1* gene is inserted into expression systems (e.g., *E. coli*, mammalian cells, or insect cells) to produce purified OPN with controlled post-translational modifications. Mammalian systems (e.g., HEK293 cells) are preferred for replicating human-like glycosylation and phosphorylation patterns critical for receptor binding and signaling. Affinity tags (e.g., His-tag) facilitate efficient purification while maintaining bioactivity.

Recombinant OPN enables standardized studies of its dual roles in health and disease. In cancer, it promotes metastasis by enhancing cell survival and angiogenesis, while in bone repair, it accelerates mineralization. It also serves as a biomarker for autoimmune diseases and cardiovascular conditions. Current challenges include optimizing cost-effective expression systems and characterizing isoform-specific functions. As therapeutic targeting of OPN gains momentum in oncology and regenerative medicine, recombinant variants provide essential tools for mechanistic research and drug development.