SPA Long
Description
SPA as Scintillation Proximity Assay (Biotechnology)
SPA refers to a homogeneous assay technology used to study molecular interactions (e.g., enzyme activity, receptor binding). While SPA itself is not a compound, it involves specialized scintillation proximity beads coated with agents like wheat germ agglutinin (WGA), polyethyleneimine (PEI), or streptavidin. These beads interact with radiolabeled molecules, enabling proximity-based detection .
| SPA Bead Type | Coating | Application | Core Material |
|---|---|---|---|
| PVT (Polyvinyl Toluene) | WGA, PEI, Streptavidin | Receptor binding, enzyme assays | Plastic |
| YSi (Yttrium Silicate) | WGA, PEI | Receptor binding, molecular interactions | Crystalline |
| PS (Polystyrene) | WGA, Streptavidin | High-throughput imaging assays | Plastic |
| YOx (Yttrium Oxide) | WGA, Nickel Chelate | GST-fusion protein assays | Crystalline |
Key Findings:
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SPA beads require isotopes with short decay pathlengths (e.g., tritium, iodine-125) for optimal signal detection .
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WGA-coated beads bind glycosylated proteins on cell membranes, while PEI coatings reduce non-specific binding .
SPA Therapy (Clinical/Thermal Water Treatments)
"Spa" therapy involves thermal water treatments for conditions like osteoarthritis, post-COVID-19 symptoms, or rheumatic diseases. Research highlights:
Mechanisms:
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Radon spa therapy: Modulates immune cells (e.g., Tregs, eosinophils) and reduces inflammation .
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Thermal water: Alters cytokine profiles (e.g., IL-6, TNF-α) and improves physical function .
While not directly linked to "SPA Long," sodium polyacrylate (a superabsorbent polymer) is used in drug delivery and microencapsulation:
Product Specs
Produced in E. coli, SPA Recombinant Long Form is a single, non-glycosylated polypeptide chain. This form encompasses five IgG-binding domains (E-D-A-B-C) arranged sequentially, resulting in a protein composed of 422 amino acids with a molecular weight of 46.6kDa.
Avoid repeated freeze-thaw cycles.
(a) High-performance liquid chromatography (HPLC) analysis.
(b) Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis.
Product Science Overview
Staphylococcal Protein-A (SpA) is a cell wall protein found in the bacterium Staphylococcus aureus. It is known for its ability to bind to the Fc region of immunoglobulins, particularly Immunoglobulin G (IgG). This binding property makes SpA a valuable tool in various biochemical and immunological applications, including antibody purification and immunoprecipitation.
The long form of recombinant Staphylococcal Protein-A is a non-glycosylated polypeptide chain produced in Escherichia coli (E. coli). It consists of five IgG-binding domains, labeled E, D, A, B, and C, aligned in series. This recombinant protein comprises 422 amino acids and has a molecular mass of approximately 46.6 kDa . The long form is designed to enhance its binding capacity and stability, making it suitable for various laboratory and industrial applications.
The recombinant long form of Staphylococcal Protein-A is typically produced using E. coli expression systems. The gene encoding the protein is cloned into an expression vector, which is then introduced into E. coli cells. The bacteria are cultured under conditions that promote the expression of the recombinant protein. After sufficient growth, the cells are harvested, and the protein is extracted and purified using techniques such as affinity chromatography. The final product is often lyophilized (freeze-dried) to ensure stability and ease of storage .
Staphylococcal Protein-A is widely used in the field of biotechnology and immunology. Its primary application is in the purification of antibodies. The protein’s ability to bind to the Fc region of IgG allows it to be used in affinity chromatography columns to isolate antibodies from complex mixtures. Additionally, SpA is employed in immunoprecipitation assays to pull down specific proteins from cell lysates using antibodies. It is also used in the production of affinity resins for various immunological assays .
The lyophilized form of Staphylococcal Protein-A is stable at room temperature for up to three weeks. For long-term storage, it is recommended to keep the protein desiccated at temperatures below -18°C. Upon reconstitution, the protein should be stored at 4°C for short-term use (2-7 days) and below -18°C for long-term use. To prevent degradation, it is advisable to add a carrier protein, such as human serum albumin (HSA) or bovine serum albumin (BSA), and avoid repeated freeze-thaw cycles .
