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Recombinant Proteins
Product List
Protein-A/G/L
Protein A/G/L Recombinant
Recombinant Protein-A/G/L produced in E.Coli is a single non-glycosylated polypeptide chain. Protein- A/G/L is comprised of 5 IgG-binding regions of Protein A (E-D-A-B-C), 2 of protein G (C1-C3) and 5 of Protein L (B1-B2-B3-B4-B5) containing 805 amino acids in total and having a molecular mass of 89.2kDa. Cell wall binding region, cell membrane binding region and albumin binding region have been eliminated from the recombinant Protein- A/G/L to guarantee the maximum specific IgG binding.
Shipped with Ice Packs 
Cat. No.
BT9494
Source
Escherichia Coli.
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Protein-A/G/L-Cys
Protein A/G/L-Cys Recombinant
Recombinant Protein-A/G/L produced in E.Coli is a single non-glycosylated polypeptide chain fused with a Cys at C-terminus. Protein- A/G/L is comprised of 5 IgG-binding regions of Protein A (E-D-A-B-C), 2 of protein G (C1-C3) and 5 of Protein L (B1-B2-B3-B4-B5) containing 806 amino acids in total and having a molecular mass of 89.3kDa. Cell wall binding region, cell membrane binding region and albumin binding region have been eliminated from the recombinant Protein- A/G/L to guarantee the maximum specific IgG binding.
Shipped with Ice Packs
Cat. No.
BT9560
Source
Escherichia Coli.
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Protein-G His
Protein G His Tag Recombinant
Protein G His Tag Recombinant produced in E.Coli is a 201 amino acids protein which contains amino acid 190-384 of the Streptococcus sp with a C-terminal 6-His tag, and having a molecular mass of 21.6kDa. But it migrates with an apparent molecular mass of 32kDa in SDS-PAGE.
The Protein G His Tag is purified by proprietary chromatographic techniques.
The Protein G His Tag is purified by proprietary chromatographic techniques.
Shipped with Ice Packs
Cat. No.
BT9643
Source
Escherichia Coli.
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Protein-L
Protein L Recombinant
Protein-L Recombinant produced in E.coli is a single, non-glycosylated polypeptide chain containing 365 amino acids and having a molecular mass of 40.5 kDa but it migrates with an apparent molecular mass of 45 kDa in SDS-PAGE.
The Protein-L is purified by proprietary chromatographic techniques.
Shipped with Ice Packs
Cat. No.
BT9705
Source
Escherichia Coli.
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Protein-L Cys
Protein L Cys Recombinant
Recombinant Protein-L produced in E.Coli is a single non-glycosylated polypeptide chain fused with a Cys at C-terminus. Protein-L is comprised of 5 IgG-binding regions of protein L (B1-B2-B3-B4-B5) containing 366 amino acids in total and having a molecular mass of 40.6kDa, however, it migrates with an apparent molecular mass of 46kDa on SDS-PAGE. Cell wall binding region, cell membrane binding region and albumin binding region have been eliminated from the recombinant Protein-L to guarantee the maximum specific IgG binding.
Shipped with Ice Packs
Cat. No.
BT9786
Source
Escherichia Coli.
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Protein-L Cys, His
Protein-L Cys Recombinant, His Tag
Recombinant Protein-L produced in E.Coli is a single non-glycosylated polypeptide chain fused with a 6×His tag at N-terminus and a Cys on C-terminus. Protein-L is comprised of 5 IgG-binding regions of protein L (B1-B2-B3-B4-B5) containing 373 amino acids in total and having a molecular mass of 41.6kDa, however, it migrates with an apparent molecular mass of 46kDa on SDS-PAGE. Cell wall binding region, cell membrane binding region and albumin binding region have been eliminated from the recombinant Protein-L to guarantee the maximum specific IgG binding.
Shipped with Ice Packs
Cat. No.
BT9873
Source
Escherichia Coli.
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Protein-L, His
Protein L Recombinant, His Tag
Recombinant Protein-L produced in E.Coli is a single non-glycosylated polypeptide chain fused with a 6×His tag at N-terminus. Protein-L is comprised of 5 IgG-binding regions of protein L (B1-B2-B3-B4-B5) containing 372 amino acids in total and having a molecular mass of 41.5kDa, however, it migrates with an apparent molecular mass of 46kDa on SDS-PAGE. Cell wall binding region, cell membrane binding region and albumin binding region have been eliminated from the recombinant Protein-L to guarantee the maximum specific IgG binding.
Shipped with Ice Packs
Cat. No.
BT9961
Source
Escherichia Coli.
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
SPA 33.4kDa
Staphylococcal Protein-A 33.4kDa Recombinant
SPA Recombinant produced in E.Coli is a homodimeric non-glycosylated polypeptide chains comprised of 5 IgG-binding domains E-D-A-B-C aligned in series containing 296 amino acids and having a molecular mass of 33.4kDa containing little or no carbohydrate. Cell wall binding region, cell membrane binding region and albumin binding region were removed to ensure the highest specific IgG binding.
Shipped with Ice Packs
Cat. No.
BT10045
Source
Escherichia Coli.
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
SPA Long
Staphylococcal Protein-A Long Form Recombinant
SPA Recombinant Long Form produced in E.Coli is a single non-glycosylated polypeptide chain. SPA Long Form is comprised of 5 IgG-binding domains E-D-A-B-C aligned in series containing 422 amino acids and having a molecular mass of 46.6kDa.
Shipped with Ice Packs
Cat. No.
BT10131
Source
Escherichia Coli.
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
SPA, His
Staphylococcal Protein-A Recombinant, His Tag
SPA Recombinant produced in E.Coli is a single non-glycosylated polypeptide chain fused with 6×His tag at C-terminus. SPA is comprised of 5 IgG-binding domains E-D-A-B-C aligned in series containing 306 amino acids and having a molecular mass of 34.7kDa containing little or no carbohydrate. Cell wall binding region, cell membrane binding region and albumin binding region were removed to ensure the highest specific IgG binding.
Shipped with Ice Packs
Cat. No.
BT10225
Source
Escherichia Coli.
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Introduction
Definition and Classification
Protein A is a 42 kDa surface protein originally found in the cell wall of the bacteria Staphylococcus aureus. It is encoded by the spa gene and is known for its ability to bind immunoglobulins, particularly the Fc region of IgG .
Protein G is derived from Streptococcus species and also binds to the Fc region of IgG. It has a broader binding range compared to Protein A, making it useful for different species and subclasses of IgG .
Protein A/G is a recombinant fusion protein that combines the IgG-binding domains of both Protein A and Protein G. This fusion enhances its binding capabilities, making it ideal for a wide range of IgG subclasses from various species .
Biological Properties
Key Biological Properties:
- Protein A: Composed of five homologous Ig-binding domains that fold into a three-helix bundle. It binds to the heavy chain within the Fc region of most immunoglobulins .
- Protein G: Contains multiple IgG-binding domains and binds more strongly to certain subclasses of IgG .
- Protein A/G: Combines properties of both Protein A and Protein G, providing versatile binding capabilities .
Expression Patterns and Tissue Distribution:
Biological Functions
Primary Biological Functions:
- Protein A: Disrupts opsonization and phagocytosis by binding IgG molecules in the wrong orientation .
- Protein G: Enhances immune response by binding to a broader range of IgG subclasses .
- Protein A/G: Combines the functions of both Protein A and Protein G, making it highly effective in immune response modulation .
Role in Immune Responses and Pathogen Recognition:
Modes of Action
Mechanisms with Other Molecules and Cells:
- Protein A: Binds to the Fc region of IgG, disrupting normal antibody function .
- Protein G: Binds to the Fc region of IgG, enhancing immune response .
- Protein A/G: Combines the binding mechanisms of both Protein A and Protein G .
Binding Partners and Downstream Signaling Cascades:
Regulatory Mechanisms
Regulatory Mechanisms Controlling Expression and Activity:
- Protein A: Regulation controlled by DNA topology, cellular osmolarity, and a two-component system called ArlS-ArlR .
- Protein G: Expression regulated by environmental factors in Streptococcus .
- Protein A/G: Recombinant expression regulated by genetic engineering techniques .
Transcriptional Regulation and Post-Translational Modifications:
Applications
In Biomedical Research:
- Protein A: Used in antibody purification and immunoprecipitation .
- Protein G: Preferred for purifying antibodies from various species .
- Protein A/G: Ideal for a wide range of immunological studies .
Diagnostic Tools:
- Protein A: Utilized in diagnostic assays to detect antibodies .
- Protein G: Used in diagnostic kits for its broad binding range .
- Protein A/G: Employed in various diagnostic applications due to its versatility .
Therapeutic Strategies:
Role in the Life Cycle
Role Throughout the Life Cycle:
- Protein A: Plays a role in the survival and virulence of Staphylococcus aureus .
- Protein G: Contributes to the pathogenicity of Streptococcus species .
- Protein A/G: Used in research to study protein interactions throughout various stages of life .
From Development to Aging and Disease:
