Recombinant Viral B8R Biotinylated Protein, CF

Catalog #: BT8225 Datasheet / COA / SDS

Catalog #	Availability	Size / Price	Qty
BT8225-025

Recombinant Viral B8R Biotinylated Protein Bioactivity

1 Image

Product Details

Supplemental Products

Reviews

Summary Product Datasheets Carrier Free Data Images Reconstitution Calculator Background Related Research Areas

Recombinant Viral B8R Biotinylated Protein, CF Summary

Product Specifications

Purity

>95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.

Endotoxin Level

<0.10 EU per 1 μg of the protein by the LAL method.

Activity

Measured by its ability to inhibit rhIFN-gamma mediated protection of HeLa human cervical epithelial carcinoma cells to viral lysis. Meager, A. (1987) in Lymphokines and Interferons, a Practical Approach. Clemens, M.J. et al. (eds): IRL Press. 129. Th ED₅₀ for this effect is 0.5-3 ng/mL.

Source

Chinese Hamster Ovary cell line, CHO-derived viral B8R protein
Lys18-Ser272, with a C-terminal 6-His tag

Accession #

P24770

N-terminal Sequence
Analysis

Lys18

Structure / Form

Noncovalently-linked homodimer, biotinylated via sugars

Predicted Molecular Mass

30 kDa (unlabeled)

Product Datasheets

BT8225

Product Datasheet

COA

SDS

Carrier Free

What does CF mean?

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

What formulation is right for me?

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

BT8225

Formulation	Lyophilized from a 0.2 μm filtered solution in PBS.
Reconstitution	Reconstitute at 250 μg/mL in PBS.
Shipping	The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.
Stability & 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.

Scientific Data

Bioactivity

View Larger

Both Biotinylated Recombinant Viral B8R (Catalog # BT8225) and unlabeled Recombinant Viral B8R (Catalog # 8225-BR) inhibits IFN-gamma-mediated protection of HeLa human cervical epithelial carcinoma cells to viral lysis. The ED₅₀ for this effect is 0.5-3 ng/mL. The similarity in activity highlights that the biotinylated protein is fully functional.

Reconstitution Calculator

Background: B8R

B8R is a secreted Interferon gamma (IFN-gamma ) binding protein encoded by the open reading frame of the Vaccina virus (smallpox) (1, 2). B8R is a 43 kDa protein and shares only 19% amino acid sequence identity with the extracellular region of the human IFN-gamma Receptor 1 (IFN-gamma R1). However, B8R binds IFN-gamma orthologs from multiple species including human, rat, rabbit, bovine, and chicken with high affinity, but it binds mouse IFN-gamma with low affinity (1, 3, 4). During infection,
virally-induced B8R binds and sequesters endogenous IFN-gamma, thereby suppressing the host immune response and promoting viral immune evasion (5). While B8R is not required for viral replication, it contributes significantly to Vaccinia virus virulence and is frequently inactivated prior to Vaccinia use in vaccines (5-9). IFN-gamma peptide mimetics that activate IFN-gamma R1 but are not bound and sequestered by B8R have been developed for research and therapeutic use (10, 11).

References