Recombinant Human B7-H3 His-tag Avi-tag Protein, CF

When Human B7-H3 Antibody (Catalog # AF1027) is immobilized at 1.0 μg/mL, 100 μL/well, the concentration of Biotinylated Recombinant Human B7-H3 His-tag Avi-tag (Catalog # AVI2318) that produces 50% of the optimal binding response is approximately 3-15 ng/mL.

2 μg/lane of Recombinant Human B7-H3 His-tag Avi-tag (Catalog # AVI2318) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 70-90 kDa.

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

Recombinant Human B7-H3 His-tag Avi-tag Protein, CF Summary

• Additional Information: Biotinylated long-form B7-H3 (4Ig)/B7-H3b
• Details of Functionality: Measured in a cell proliferation assay using mouse CD4⁺ cells in the presence of anti-CD3. The ED₅₀ for this effect is 3-12 μg/mL. Measured by its binding ability in a functional ELISA. When Human B7-H3 Antibody (Catalog # AF1027) is immobilized at 1.0 μg/mL, 100 μL/well, the concentration of Biotinylated Recombinant Human B7‑H3 His-tag Avi-tag (Catalog # AVI2318) that produces 50% of the optimal binding response is approximately 3 -15 ng/mL.
• Source: Human embryonic kidney cell, HEK293-derived human B7-H3 protein
  

  Human B7-H3 (Leu29-Thr461) Accession # Q5ZPR3-1	HHHHHH	Avi-tag
  N-terminus		C-terminus

• Accession #: Q5ZPR3-1
• N-terminal Sequence: Leu29
• Structure / Form: 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: <1.0 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
  • Bioactivity2
• Theoretical MW: 49 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: 70-90 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 200 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 His-tag Avi-tag Protein, CF

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

Background

Human B7 homolog 3 (B7-H3) is a member of the B7 family of immune proteins that provide signals for the regulation of immune responses (1 - 3). Other family members include B7-1, B7-2, B7-H1/PD-L1, B7-H2, and PD-L2. B7 family proteins are type I transmembrane immunoglobulin (Ig) superfamily members that contain extracellular Ig V‑like and Ig C‑like domains with a short cytoplasmic tail. Among the family members there is about 20 - 40% amino acid (aa) sequence identity. B7-H3 was initially reported to be a 316 aa type I transmembrane precursor protein that contained a signal sequence, an extracellular region with one V‑type and one C‑type Ig domain, a transmembrane segment and a short cytoplasmic tail (1). Subsequent studies have identified a second 110 kDa form whose precursor is 534 aa in length. Termed 4IgB7-H3 or B7-H3b, this molecule has two additional Ig-like domains (one V‑type and one C‑type) and shows a ubiquituous expression pattern (4, 5). It would appear that the human 4Ig form is the principal, if not the only form of B7-H3 (5). Its precursor contains a 26 aa signal sequence, a 435 aa extracellular region, a 31 aa transmembrane domain, and a 42 aa cytoplasmic tail. The four Ig-like domains alternate between V‑type and C‑type, and apparently are the consequence of a V‑C type tandem duplication (4, 5). B7-H3b is expressed on dendritic cells as well as activated T, B and NK cells (5). The mouse gene differs from that of human in that it cannot code for four Ig-like domains; only a V‑type:C‑type pair (4). Human B7-H3b binding to an undefined receptor has shown to be inhibitory to NK cells and cytokine release (6). It also seems to be required for late stage osteoblast differentiation (7).

1. Chapoval, A.I. et al. (2001) Nat. Immunol. 2:269.
2. Sharpe, A.H. and G.J. Freeman (2002) Nat. Rev. Immunol. 2:116.
3. Coyle, A. and J.Gutierrez-Ramos (2001) Nat. Immunol. 2:203.
4. Sun, M. et al. (2002) J. Immunol. 168:6294.
5. Steinberger, P. et al. (2004) J. Immunol. 172:2352.
6. Prasad, D.V.R. et al. (2004) J. Immunol. 173:2500.
7. Suh, W-K. et al. (2004) Proc. Natl. Acad. Sci. USA 101:12969.

Bioinformatics

• Uniprot:
  • Q5ZPR3-1()