Osteopontin/OPN Protein, Human (HEK293, His)

Osteopontin/OPN is a secretory glycophosphoprotein belonging to the SIBLING family. It contains RGD sequences and phosphorylation sites and can bind to integrins α_vβ₃, α₄β₁ and CD44 receptors. Osteopontin/OPN regulates cell adhesion and migration through receptor-mediated regulation, activates MAPK/ERK and PI3K-AKT to promote tumor invasion, and upregulates TIMP-1/2 to inhibit MMPs and protect cartilage. Osteopontin/OPN can be used in the study of osteoarthritis, liver cancer, etc^[1][2][3].

Osteopontin/OPN is a 44-75 kDa secreted glycophosphoprotein belonging to the small integrin binding ligand N-glycoprotein (SIBLING) family. It contains the RGD (Arg-Gly-Asp) sequence and multiple phosphorylation sites, and can bind to integrin α_vβ₃, α₄β₁, and CD44 receptors^[1][2][3].
Osteopontin/OPN regulates cell adhesion, migration, proliferation, and matrix remodeling through receptor-mediated regulation, and participates in inflammation, bone metabolism, and tumor progression. Osteopontin/OPN can upregulate TIMP-1 and TIMP-2, inhibit the activity of matrix metalloproteinases (MMPs), and protect chondrocytes. Osteopontin/OPN also induces the release of inflammatory factors through the NF-κB pathway, participating in the pathological process of osteoarthritis (OA)^[1]. At the same time, Osteopontin/OPN activates the MAPK/ERK and PI3K-AKT pathways, promoting tumor cell invasion (such as osteosarcoma OS-732 cell migration)^[2]; Osteopontin/OPN is induced by TNF-α and IL-1β upstream, and activates the integrin-cytoskeleton signaling cascade downstream^[3].
Osteopontin/OPN can be used in the study of osteoarthritis (OA). Intra-articular OPN inhibits MMPs by upregulating TIMP-1/2, delaying cartilage degradation^[1]. Osteopontin/OPN can also be used in the study of tumor diagnosis and prognosis. Preoperative plasma OPN level is an independent predictor of hepatocellular carcinoma (HCC) recurrence and poor prognosis (critical value 200 ng/mL)^[3]; while antisense OPN RNA can inhibit the tumorigenicity of osteosarcoma cells, prolong tumor latency and reduce tumor weight in nude mice^[2].

Measured by the ability of the immobilized protein to support the adhesion of HEK293 human embryonic kidney cells. When 1 x 10^5 cells/well are added to Recombinant Human Osteopontin coated plates, cell adhesion is enhanced in a dose dependent manner after 1 hour incubation at 37 °C. The ED₅₀ for this effect is <0.3 μg/mL.

• 
  Measured by the ability of the immobilized protein to support the adhesion of HEK293 human embryonic kidney cells. When 1 x 10⁵ cells/well are added to Recombinant Human Osteopontin coated plates, cell adhesion is enhanced in a dose dependent manner after 1 hour incubation at 37 °C. The ED₅₀ for this effect is 0.1486 μg/mL, corresponding to a specific activity is 6729.475 units/mg.

Human

HEK293

C-6*His

P10451-1 (I17-N314)

6696  [NCBI]

Full Length of Isoform-1 Mature Protein

IPVKQADSGSSEEKQLYNKYPDAVATWLNPDPSQKQNLLAPQNAVSSEETNDFKQETLPSKSNESHDHMDDMDDEDDDDHVDSQDSIDSNDSDDVDDTDDSHQSDESHHSDESDELVTDFPTDLPATEVFTPVVPTVDTYDGRGDSVVYGLRSKSKKFRRPDIQYPDATDEDITSHMESEELNGAYKAIPVAQDLNAPSDWDSRGKDSYETSQLDDQSAETHSHKQSRLYKRKANDESNEHSDVIDSQELSKVSREFHSHEFHSHEDMLVVDPKSKEEDKHLKFRISHELDSASSEVN

Approximately 50-69 kDa due to the glycosylation

• 
  Greater than 95% as determined by reducing SDS-PAGE.

Lyophilized powder

Lyophilized from a 0.2 μm filtered solution of PBS, pH 7.4 or PBS, pH 7.4, 8% trehalose.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O. For long term storage it is recommended to add a carrier protein (0.1% BSA, 5% HSA, 10% FBS or 5% Trehalose).

Stored at -20°C for 2 years from date of receipt. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.

• [1]. Zhang FJ, et al. Effect of osteopontin on TIMP-1 and TIMP-2 mRNA in chondrocytes of human knee osteoarthritis in vitro. Exp Ther Med. 2014 Aug;8(2):391-394.  [Content Brief]

  [2]. Liu SJ, et al. The inhibition of in vivo tumorigenesis of osteosarcoma (OS)-732 cells by antisense human osteopontin RNA. Cell Mol Biol Lett. 2008;13(1):11-9.  [Content Brief]

  [3]. Zhang H, et al. The prognostic significance of preoperative plasma levels of osteopontin in patients with hepatocellular carcinoma. J Cancer Res Clin Oncol. 2006 Nov;132(11):709-17.  [Content Brief]