SPARC Human

SPARC, which stands for 'secreted protein, acidic and rich in cysteine', is also referred to as osteonectin or BM-40. It is the first identified member of a family of secreted matricellular proteins that share a similar domain structure. This protein consists of 303 amino acids, has a molecular weight of 43 kDa, and comprises a 17 amino acid signal sequence, an N-terminal acidic region capable of calcium binding, a follistatin domain containing Kazal-like sequences, and a C-terminal extracellular calcium (EC) binding domain with two EF-hand motifs. SPARC is produced by various cell types, including fibroblasts, capillary endothelial cells, platelets, and macrophages, particularly in areas undergoing tissue morphogenesis and remodeling. While SPARC exhibits context-dependent effects, it generally inhibits cell adhesion, spreading, and proliferation, while promoting the formation of the collagen matrix. In endothelial cells, SPARC disrupts focal adhesions and binds to and sequesters both PDGF and VEGF. SPARC is highly expressed in bone tissue, where it plays a role in promoting osteoblast differentiation and inhibiting adipogenesis.

Recombinant Human Secreted Protein Acidic & Rich in Cysteine, produced in E. coli, is a single, non-glycosylated polypeptide chain comprising 286 amino acids, with a molecular weight of 32.7 kDa. The purification of SPARC is achieved using proprietary chromatographic methods.

Sterile Filtered White lyophilized (freeze-dried) powder.

Lyophilized from a 0.2 μm filtered concentrated solution in phosphate-buffered saline (PBS) at pH 7.4.

To reconstitute the lyophilized SPARC, it is recommended to dissolve it in sterile 18 MΩ-cm H₂O at a concentration of at least 100 μg/ml. This solution can be further diluted in other aqueous solutions as needed.

Lyophilized SPARC remains stable at room temperature for up to 3 weeks; however, for long-term storage, it should be stored desiccated at a temperature below -18°C. Once reconstituted, Secreted Protein Acidic & Rich in Cysteine should be stored at 4°C for no longer than 2-7 days. For future use, it should be stored at -18°C. Avoid repeated freeze-thaw cycles.

The purity is determined to be greater than 98.0% using the following methods:
(a) Reverse-phase high-performance liquid chromatography (RP-HPLC) analysis.
(b) Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis.

The ED50, which represents the effective concentration required to inhibit 50% of cell growth, was determined to be less than 3.0 μg/mL in Mv1Lu mink lung epithelial cells. This corresponds to a specific activity greater than 333 IU/mg.

Osteonectin, ON, Basement-membrane protein 40, BM-40, SPARC, Secreted Protein acidic and Rich in Cysteine.

Escherichia Coli.

APQQEALPDE TEVVEETVAE VTEVSVGANP VQVEVGEFDD GAEETEEEVV AENPCQNHHC KHGKVCELDE NNTPMCVCQD PTSCPAPIGE FEKVCSNDNK TFDSSCHFFA TKCTLEGTKK GHKLHLDYIG PCKYIPPCLD SELTEFPLRM RDWLKNVLVT LYERDEDNNL LTEKQKLRVK KIHENEKRLE AGDHPVELLA RDFEKNYNMY IFPVHWQFGQ LDQHPIDGYL SHTELAPLRA PLIPMEHCTT RFFETCDLDN DKYIALDEWA GCFGIKQKDI DKDLVI.