Recombinant Biotinylated Human B7-H3 (4Ig) / B7-H3b Protein, His,Avitag™, 25 µg

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. 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. 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.

Source
Recombinant Biotinylated Human B7-H3 (4Ig), His,Avitag (B7B-H82E8) is expressed from human 293 cells (HEK293). It contains AA Gly 27 - Thr 461 (Accession # Q5ZPR3-1).
Predicted N-terminus: Gly 27

Molecular Characterization
This protein carries a polyhistidine tag at the C-terminus, followed by an Avi tag (Avitag™).
The protein has a calculated MW of 50.3 kDa. The protein migrates as 65-80 kDa when calibrated against Star Ribbon Pre-stained Protein Marker under reducing (R) condition (SDS-PAGE) due to glycosylation.

Biotinylation
Biotinylation of this product is performed using Avitag™ technology. Briefly, the single lysine residue in the Avitag is enzymatically labeled with biotin.
Biotin:Protein Ratio
Passed as determined by the HABA assay / binding ELISA.

Endotoxin
Less than 1.0 EU per μg by the LAL method.

Purity
>95% as determined by SDS-PAGE.
>90% as determined by SEC-MALS.

Formulation
Lyophilized from 0.22 μm filtered solution in PBS, pH7.4 with trehalose as protectant.

Reconstitution
Please see Certificate of Analysis for specific instructions.
For best performance, we strongly recommend you to follow the reconstitution protocol provided in the CoA.

Storage
For long term storage, the product should be stored at lyophilized state at -20°C or lower.
Please avoid repeated freeze-thaw cycles.
This product is stable after storage at:
-20°C to -70°C for 12 months in lyophilized state;
-70^°C for 3 months under sterile conditions after reconstitution.

Bioactivity
Please refer to product data sheet.

Clinical and Translational Updates

(1) "Dimerization of the 4Ig isoform of B7-H3 in tumor cells mediates enhanced proliferation and tumorigenic signaling"
Sutton, Glazer, Muzzioli et al
Commun Biol (2024) 7 (1), 21
(2) "B7-H3 in Pediatric Tumors: Far beyond Neuroblastoma"
Bottino, Vitale, Dondero et al
Cancers (Basel) (2023) 15 (13)
(3) "Expression characteristic of 4Ig B7-H3 and 2Ig B7-H3 in acute myeloid leukemia"
Zhang, Zhang, Qian et al
Bioengineered (2021) 12 (2), 11987-12002
Showing 1-3 of 11 papers.