SPARC Human, Sf9
Description
Molecular Structure and Characteristics
SPARC Human, Sf9 is a glycosylated polypeptide chain comprising 295 amino acids (residues 18–303) with a molecular mass of 33.8 kDa . Key structural features include:
-
N-terminal acidic domain: Binds calcium ions and modulates cell-matrix interactions .
-
Follistatin domain: Contains Kazal-like sequences involved in protease inhibition .
-
C-terminal extracellular calcium-binding domain: Features two EF-hand motifs for collagen binding .
-
His-tag: A 9-amino acid histidine tag at the C-terminus facilitates purification .
Key Production Steps:
-
Cloning: SPARC cDNA is inserted into a baculovirus vector.
-
Transfection: Sf9 cells are infected with recombinant baculovirus.
-
Harvesting: Secreted SPARC is collected from cell culture media.
-
Purification: Proprietary chromatographic techniques, including affinity chromatography leveraging the His-tag .
Table 2: Production Metrics
| Parameter | Specification | Source |
|---|---|---|
| Yield | ~0.5 mg/mL in optimized conditions | |
| Purity | >90% (SDS-PAGE verified) | |
| Storage | -20°C (with 10% glycerol to prevent aggregation) |
Functional Roles in Disease and Therapy
SPARC Human, Sf9 is implicated in cancer progression, drug resistance, and tissue remodeling:
-
Cancer Resistance:
-
Therapeutic Target:
Table 3: Key Research Findings
Applications in Biomedical Research
-
Drug Delivery: SPARC’s affinity for collagen and albumin makes it a candidate for nanoparticle-based drug targeting .
-
Biomaterial Engineering: Used to functionalize scaffolds for bone regeneration due to calcium-binding properties .
-
Diagnostics: Elevated SPARC levels in serum correlate with advanced HCC and poor prognosis .
Comparative Analysis with Other SPARC Variants
SPARC Human, Sf9 differs from E. coli-derived SPARC (e.g., PRO-2623 vs. PRO-2658):
-
Glycosylation: Sf9-produced SPARC retains native glycosylation absent in E. coli versions, critical for ligand interactions .
-
Solubility: Sf9-derived SPARC is stored in PBS + glycerol, while E. coli variants require reconstitution from lyophilized powder .
Future Directions
Product Specs
SPARC, also known as secreted protein acidic and rich in cysteine, osteonectin, or basement-membrane protein 40, is encoded by the SPARC gene in humans. This glycoprotein resides in bones and exhibits calcium-binding properties. Osteoblasts secrete osteonectin during bone formation and mineralization, where it facilitates the development of mineral crystals. Beyond calcium, SPARC has demonstrated an ability to bind collagen.
Recombinant Human SPARC, expressed in Sf9 Baculovirus cells, is a single, glycosylated polypeptide chain comprising 295 amino acids (residues 18-303). With a molecular weight of 33.8 kDa, it features a 9 amino acid His-tag at the C-terminus. Purification is achieved through proprietary chromatographic techniques.
The SPARC protein solution is provided at a concentration of 0.5 mg/ml in Phosphate-Buffered Saline (pH 7.4) with 10% glycerol.
For short-term storage (2-4 weeks), maintain the product at 4°C. For extended storage, freeze at -20°C. The addition of a carrier protein (0.1% HSA or BSA) is recommended for long-term storage. Avoid repeated freeze-thaw cycles.
Purity exceeds 90.0% as determined by SDS-PAGE analysis.
SPARC, Basement-membrane protein 40, BM-40, Osteonectin, ON, Secreted protein acidic and rich in cysteine, OI17.
ADPAPQQEAL PDETEVVEET VAEVTEVSVG ANPVQVEVGE FDDGAEETEE EVVAENPCQN
HHCKHGKVCE LDENNTPMCV CQDPTSCPAP IGEFEKVCSN DNKTFDSSCH FFATKCTLEG
TKKGHKLHLD YIGPCKYIPP CLDSELTEFP LRMRDWLKNV LVTLYERDED NNLLTEKQKL
RVKKIHENEK RLEAGDHPVE LLARDFEKNY NMYIFPVHWQ FGQLDQHPID GYLSHTELAP
LRAPLIPMEH CTTRFFETCD LDNDKYIALD EWAGCFGIKQ KDIDKDLVIH HHHHH
Product Science Overview
The SPARC gene spans approximately 25.9 kb on human chromosome 5q31.3–q32. It consists of 10 exons and 9 introns, with the first non-coding exon separated from the coding exons by a large 10.6 kb intron . The gene produces a 40 kDa acidic and cysteine-rich glycoprotein composed of a single polypeptide chain that can be divided into four domains:
SPARC is predominantly secreted by non-epithelial cells, including endothelial and smooth muscle cells, osteoblasts, and platelets. It is highly expressed in developing and remodeling tissues, such as bone, gut, ovary, testis, mammary gland, and healing wounds . The protein is involved in several key biological processes:
- Bone Mineralization: SPARC binds to collagen and hydroxyapatite, promoting mineralization and crystal formation in bone .
- Cell-Matrix Interactions: It modulates cell attachment, deposition of extracellular matrix (ECM), and matrix mineralization .
- Angiogenesis: SPARC plays a role in the formation of new blood vessels .
- Tumor Progression: Overexpression of SPARC has been observed in various cancers, including breast, prostate, colon, and pancreatic cancers. It aids in tumor cell proliferation, migration, and angiogenesis .
Recombinant SPARC is produced using the Sf9 insect cell expression system. This system is widely used for producing recombinant proteins due to its ability to perform post-translational modifications similar to those in mammalian cells. The recombinant SPARC retains the functional properties of the native protein, making it valuable for research and therapeutic applications.
Recombinant SPARC is used in various research fields, including:
- Cancer Research: Studying the role of SPARC in tumor progression and metastasis.
- Bone Biology: Investigating its function in bone mineralization and ECM interactions.
- Wound Healing: Exploring its role in tissue repair and regeneration.
