Recombinant Human B7-H3 Fc Chimera Avi-tag Protein, CF

When Human B7-H3 Antibody (AF1027) is immobilized at 1 μg/mL, 100 μL/well, the concentration of Biotinylated Recombinant Human B7-H3 Fc Chimera Avi-tag (Catalog # AVI1027) that produces 50% of the optimal binding response is approximately 3-18 ng/mL.

2 μg/lane of Biotinylated Recombinant Human B7-H3 Fc Chimera Avi-tag Protein (Catalog # AVI1027) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 62-74 kDa and 120-150 kDa, respectively.

• Reactivity: Hu
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant Human B7-H3 Fc Chimera Avi-tag Protein, CF Summary

• Additional Information: Biotinylated
• Details of Functionality: Measured by its ability to inhibit anti-CD3 antibody induced IL-2 or IFN-gamma secretion by human T cells. The ED₅₀ for this effect is 1-10 µg/mL. Measured by its binding ability in a functional ELISA. When Human B7-H3 Antibody (Catalog # AF1027) is immobilized at 1 μg/mL, 100 μL/well, the concentration of Biotinylated Recombinant Human B7-H3 Fc Chimera Avi-tag (Catalog # AVI1027) that produces 50% of the optimal binding response is approximately 3-18 ng/mL.
• Source: Chinese Hamster Ovary cell line, CHO-derived human B7-H3 protein
  

  Human B7-H3 (Leu29-Pro245) Accession # NP_079516.1	DIEGRMD	Human IgG1 (Pro100-Lys330)	Avi-tag
  N-terminus			C-terminus

• Accession #: NP_079516.1
• N-terminal Sequence: Leu29
• Structure / Form: Disulfide-linked homodimer, biotinylated via Avi-tag
• Protein/Peptide Type: Recombinant Proteins
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
  • Bioactivity2
• Theoretical MW: 52 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 62-74 kDa, under reducing conditions

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining
• Reconstitution Instructions: Reconstitute at 500 μg/mL in PBS.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Human B7-H3 Fc Chimera Avi-tag Protein, CF

• B7H3
• B7-H3
• B7H34Ig-B7-H3
• B7-H3B7 homolog 3
• CD276 antigen
• CD276 molecule
• CD276
• Costimulatory molecule

Background

T cells require a signal induced by the engagement of the T cell receptor and a "co-stimulatory" signal(s) through distinct T cell surface molecules for optimal T cell expansion and activation. Members of the B7 superfamily of counter-receptors were identified by their ability to interact with co-stimulatory molecules found on the surface of T cells. Members of the B7 superfamily include B7-1 (CD80), B7-2 (CD86), B7-H1 (PD-L1), B7-H2 (B7RP-1), PD-L2 (B7-DC), and B7-H3 (1). Human B7-H3 was originally identified as a 316 amino acid (aa) type I membrane precursor protein with a putative 28 aa signal peptide, a 217 aa extracellular region containing one V-like and one C-like Ig domain, a transmembrane region, and a 45 aa cytoplasmic domain (2). Subsequently, a second dominantly expressed form of human B7-H3, containing a splice variation that duplicates the V-like and C-like Ig domains, was found. The 534 aa splice variant of B7-H3 has been referred to as B7-H3b, 4Ig‑B7‑H3, and B7‑H3VCVC (3𔂯). RT-PCR transcripts for both B7-H3 and 4Ig‑B7‑H3 have been found in all tissues except peripheral blood leukocytes (5). Southern blot analysis indicates that the 4Ig-B7-H3 isoform of B7‑H3 is the predominate isoform expressed in human tissues (5). In mouse, only a single form of B7-H3 containing one V-like and one C-like Ig domain was detected (5). Mouse and human B7-H3 share 87% aa sequence identity (3). B7-H3 has been shown to be expressed at very high levels in immature dendritic cells, at moderate levels on mature dendritic cells, LPS stimulated immature dendritic cells and LPS stimulated monocytes, and at low levels on resting monocytes (3). B7-H3 binds to activated T cells via an as yet unidentified receptor. In assays using sub-optimal amount so anti-CD3 stimulation, 2Ig‑B7‑H3 enhances T cell proliferation, T cell interferon-gamma (IFN‑gamma ) production, and cytotoxic T cells induction (2). In an assay in which cells were transfected with 4Ig-B7-H3 or 2Ig‑B7‑H3 and anti-CD3 antibody was added, neither 4Ig-B7-H3 nor 2Ig‑B7‑H3 was capable of co‑stimulating T cell proliferation or IFN-gamma production (4, 5). Our Avi-tag Biotinylated human B7-H3 features biotinylation at a single site contained within the Avi-tag, a unique 15 amino acid peptide. Protein orientation will be uniform when bound to streptavidin-coated surface due to the precise control of biotinylation and the rest of the protein is unchanged so there is no interference in the protein's bioactivity.

1. Coyle, A.J. and J.-C. Gutierrez-Ramos (2001) Nature Immunol. 2:203.
2. Chapoval, A.I. et al. (2001) Nature Immunol. 2:269.
3. Sun, M. et al. (2002) J. Immunol. 168:6294.
4. Steinberger, et al. (2004) J. Immunol. 172:2352.
5. Ling, V. et al. (2003) Genomic 82:365.

Bioinformatics

• Uniprot:
  • NP_079516.1()