| Field | Specification |
|---|---|
| Mfr No | |
| Activity | |
| Alternative Names | (Human leukocyte antigen DRB1)(HLA-DRB1) |
| Conjugate | |
| Endotoxin Level | |
| Expression System | |
| Form | Liquid or Lyophilized powder |
| Molecular Weight | |
| Product Type | |
| Protein Length | |
| Purity | |
| Reconstitution | |
| Species | |
| Storage | |
| Target | |
| UniProt # |
Overview
Recombinant Human HLA class II histocompatibility antigen, DRB1 beta chain (HLA-DRB1), partial is a recombinant protein preparation from Homo sapiens (Human) designed for use in assay development, binding studies, and functional characterization. Key attributes such as expression system, expressed region, and affinity tag(s) help researchers match the reagent to specific experimental readouts.
Key elements and design rationale
- Expression system: E.coli expression is commonly used for rapid, scalable production. For targets that require glycosylation or other post-translational modifications, consider how a prokaryotic system may affect folding or activity.
- Expression region: The expressed fragment (30-227aa) focuses the reagent on a defined domain/segment, which can influence binding interfaces and epitope availability.
- Tag(s)/format: His/Myc tags can support purification and detection in pull-down or binding assays; confirm that the tag position does not interfere with the interaction of interest.
- Purity: ≥90% (SDS-PAGE) provides a quick checkpoint for reagent quality in downstream analytical workflows.
- Form: Supplied as Liquid or Lyophilized powder; select the format that best fits your lab’s handling and aliquoting preferences.
Recombinant design choices (expression host, fragment boundaries, and tag configuration) help balance yield, solubility, and assay compatibility. Choose conditions and controls that match the recombinant format to your experimental question.
Biological background
HLA-DRB1 has been reported to be involved in A beta chain of antigen-presenting major histocompatibility complex class II (MHCII) molecule. In complex with the alpha chain HLA-DRA, displays antigenic peptides on professional antigen presenting cells (APCs) for recognition by alpha-beta T cell receptor (TCR) on HLA-DRB1-restricted CD4-positive T cells. This guides antigen-specific T-helper effector functions, both antibody-mediated immune response and macrophage activation, to ultimately eliminate the infectious agents and transformed cells. Typically presents extracellular peptide antigens of 10 to 30 amino acids that arise from proteolysis of endocytosed antigens in lysosomes. In the tumor microenvironment, presents antigenic peptides that are primarily generated in tumor-resident APCs likely via phagocytosis of apoptotic tumor cells or macropinocytosis of secreted tumor proteins. Presents peptides derived from intracellular proteins that are trapped in autolysosomes after macroautophagy, a mechanism especially relevant for T cell selection in the thymus and central immune tolerance. The selection of the immunodominant epitopes follows two processing modes: 'bind first, cut/trim later' for pathogen-derived antigenic peptides and 'cut first, bind later' for autoantigens/self-peptides. The anchor residue at position 1 of the peptide N-terminus, usually a large hydrophobic residue, is essential for high affinity interaction with MHCII molecules. ; Allele DRB1*01:01: Displays an immunodominant epitope derived from Bacillus anthracis pagA/protective antigen, PA (KLPLYISNPNYKVNVYAVT), to both naive and PA-specific memory CD4-positive T cells. Presents immunodominant HIV-1 gag peptide (FRDYVDRFYKTLRAEQASQE) on infected dendritic cells for recognition by TRAV24-TRBV2 TCR on CD4-positive T cells and controls viral load. May present to T-helper 1 cells several HRV-16 epitopes derived from capsid proteins VP1 (PRFSLPFLSIASAYYMFYDG) and VP2 (PHQFINLRSNNSATLIVPYV), contributing to viral clearance. Displays commonly recognized peptides derived from IAV external protein HA (PKYVKQNTLKLAT and SNGNFIAPEYAYKIVK) and from internal proteins M, NP and PB1, with M-derived epitope (GLIYNRMGAVTTEV) being the most immunogenic. Presents a self-peptide derived from COL4A3 (GWISLWKGFSF) to TCR (TRAV14 biased) on CD4-positive, FOXP3-positive regulatory T cells and mediates immune tolerance to self. May present peptides derived from oncofetal trophoblast glycoprotein TPBG 5T4, known to be recognized by both T-helper 1 and regulatory T cells. Displays with low affinity a self-peptide derived from MBP (VHFFKNIVTPRTP). ; Allele DRB1*03:01: May present to T-helper 1 cells an HRV-16 epitope derived from capsid protein VP2 (NEKQPSDDNWLNFDGTLLGN), contributing to viral clearance. Displays self-peptides derived from retinal SAG (NRERRGIALDGKIKHE) and thyroid TG (LSSVVVDPSIRHFDV). Presents viral epitopes derived from HHV-6B gH/U48 and U85 antigens to polyfunctional CD4-positive T cells with cytotoxic activity implicated in control of HHV-6B infection. Presents several immunogenic epitopes derived from C. tetani neurotoxin tetX, playing a role in immune recognition and long-term protection. ; Allele DRB1*04:01: Presents an immunodominant bacterial epitope derived from M. tuberculosis esxB/culture filtrate antigen CFP-10 (EISTNIRQAGVQYSR), eliciting CD4-positive T cell effector functions such as IFNG production and cytotoxic activity. May present to T-helper 1 cells an HRV-16 epitope derived from capsid protein VP2 (NEKQPSDDNWLNFDGTLLGN), contributing to viral clearance. Presents tumor epitopes derived from melanoma-associated TYR antigen (QNILLSNAPLGPQFP and DYSYLQDSDPDSFQD), triggering CD4-positive T cell effector functions such as GMCSF production. Displays preferentially citrullinated self-peptides derived from VIM (GVYATR/citSSAVR and SAVRAR/citSSVPGVR) and ACAN (VVLLVATEGR/ CitVRVNSAYQDK). Displays self-peptides derived from COL2A1. ; Allele DRB1*04:02: Displays native or citrullinated self-peptides derived from VIM. ; Allele DRB1*04:04: May present to T-helper 1 cells several HRV-16 epitopes derived from capsid proteins VP1 (HIVMQYMYVPPGAPIPTTRN) and VP2 (RGDSTITSQDVANAVVGYGV), contributing to viral clearance. Displays preferentially citrullinated self-peptides derived from VIM (SAVRAR/citSSVPGVR). ; Allele DRB1*04:05: May present to T-helper 1 cells an immunogenic epitope derived from tumor-associated antigen WT1 (KRYFKLSHLQMHSRKH), likely providing for effective antitumor immunity in a wide range of solid and hematological malignancies. ; Allele DRB1*05:01: Presents an immunodominant HIV-1 gag peptide (FRDYVDRFYKTLRAEQASQE) on infected dendritic cells for recognition by TRAV24-TRBV2 TCR on CD4-positive T cells and controls viral load. ; Allele DRB1*07:01: Upon EBV infection, presents latent antigen EBNA2 peptide (PRSPTVFYNIPPMPLPPSQL) to CD4-positive T cells, driving oligoclonal expansion and selection of a dominant virus-specific memory T cell subset with cytotoxic potential to directly eliminate virus-infected B cells. May present to T-helper 1 cells several HRV-16 epitopes derived from capsid proteins VP1 (PRFSLPFLSIASAYYMFYDG) and VP2 (VPYVNAVPMDSMVRHNNWSL), contributing to viral clearance. In the context of tumor immunesurveillance, may present to T-helper 1 cells an immunogenic epitope derived from tumor-associated antigen WT1 (MTEYKLVVVGAVGVGKSALTIQLI), likely providing for effective antitumor immunity in a wide range of solid and hematological malignancies. In metastatic epithelial tumors, presents to intratumoral CD4-positive T cells a KRAS neoantigen (MTEYKLVVVGAVGVGKSALTIQLI) carrying G12V hotspot driver mutation and may mediate tumor regression. ; Allele DRB1*11:01: Displays an immunodominant HIV-1 gag peptide (FRDYVDRFYKTLRAEQASQE) on infected dendritic cells for recognition by TRAV24-TRBV2 TCR on CD4-positive T cells and controls viral load. May present to T-helper 1 cells an HRV-16 epitope derived from capsid protein VP2 (SDRIIQITRGDSTITSQDVA), contributing to viral clearance. Presents several immunogenic epitopes derived from C. tetani neurotoxin tetX, playing a role in immune recognition and longterm protection. In the context of tumor immunesurveillance, may present tumor-derived neoantigens to CD4-positive T cells and trigger anti-tumor helper functions. ; Allele DRB1*13:01: Presents viral epitopes derived from HHV-6B antigens to polyfunctional CD4-positive T cells implicated in control of HHV-6B infection. ; Allele DRB1*15:01: May present to T-helper 1 cells an HRV-16 epitope derived from capsid protein VP2 (SNNSATLIVPYVNAVPMDSM), contributing to viral clearance. Displays a self-peptide derived from MBP (ENPVVHFFKNIVTPR). May present to T-helper 1 cells an immunogenic epitope derived from tumor-associated antigen WT1 (KRYFKLSHLQMHSRKH), likely providing for effective antitumor immunity in a wide range of solid and hematological malignancies. ; Allele DRB1*15:02: Displays an immunodominant HIV-1 gag peptide (FRDYVDRFYKTLRAEQASQE) on infected dendritic cells for recognition by TRAV24-TRBV2 TCR on CD4-positive T cells and controls viral load. May present to T-helper 1 cells an immunogenic epitope derived from tumor-associated antigen WT1 (KRYFKLSHLQMHSRKH), likely providing for effective antitumor immunity in a wide range of solid and hematological malignancies. ; (Microbial infection) Acts as a receptor for Epstein-Barr virus on lymphocytes.. When interpreting results, consider species context, domain architecture, and whether the recombinant format represents full-length or a defined region.
Research relevance and current trends
- Antigen and virulence-factor studies that compare strain- or domain-specific binding and immune recognition.
- Use of recombinant proteins as standards for quantitative assays and serology-oriented method development.
Common research applications
- Binding and interaction assays: quantify partner binding and rank conditions using plate-based formats or biophysical methods (SPR/BLI).
- Cell-based functional studies: evaluate dose–response and time-course effects in relevant cell systems when the target acts extracellularly or through receptor engagement.
- Assay development: use as a standard, spike-in control, or positive control where consistent specifications are required.
Interpretation typically relies on relative comparisons (treated vs control, mutant vs wild-type, or dose/time series) using consistent sample handling and appropriate normalization.
Notes for experimental interpretation
- Post-translational modifications: expression system can affect glycosylation and processing; interpret differences cautiously when comparing to native protein.
- Isoforms and domains: expressed regions may not capture all isoform-specific features; match fragment boundaries to your assay’s binding site.
- Controls: include blank matrix controls, tag-only controls (where relevant), and orthogonal readouts (e.g., WB/qPCR/ELISA) to support interpretation.
What is protein expression and purification?
Why is there no/low protein expression?
b. Rare codons. You should optimize codons, use strains supplementing rare codons, induce at lower temperature or grow in poor media.
c. Protein toxicity. You should use promoters with tighter regulation or lower plasmid copy number. Use pLysS/pLysE bearing strains in T7-based systems or strains that are better for the expression of toxic proteins. Start induction at high OD and shorten induction time. Add glucose when using expression vectors containing lac-based promoters.
How to avoid inclusion bodies and improve soluble expression?
b. Incorrect disulfide bond formation. You should add fusion partners, including thioredoxin, DsbA, DsbC. Clone in a vector containing secretion signal peptide to cell periplasm. Use gamiB (DE3)strains with oxidative cytoplasmic environment. Lower inducer concentration and induction temperature.
c. Incorrect folding. You should use a fusion partner. Co-express with molecular chaperones. Use strains with cold-adapted chaperones. Supplement media with chemical chaperones and cofactors. Reduce the inducer concentration and add fresh media. Induce for a shorter time at low temperature.
Why is the molecular weight of protein smaller than the predicted?
b. Imbalanced translation process of fusion protein. You should change another fusion tag or move fusion tag to C-terminal. You should induce for a shorter time at low temperature or change to poor media.
c. Protein degradation. You should replace specific protease sites. Use protease deficient strains. Induce at high OD. You should induce for a shorter time at low temperature or use protease inhibitors when breaking cells.
Why is the actual band size different from the predicted?
b. Post-translational cleavage. Many proteins are synthesized as pro-proteins, and then cleaved to give the active form.
c. Splice variants. Alternative splicing may create different sized proteins from the same gene.
d. Relative charge. The composition of amino acids have different relative charge which will affect the electrophoretic mobility.
e. Multimers such as dimerisation of a protein. This is usually prevented in reducing conditions, although strong interactions can result in the appearance of higher bands.
f. Protein structure such as disulfide bond, protein secondary structure or protein 3D structure formation.
g. Hydrophobic proteins, such as transmembrane proteins, may have difficulties in migrating into the gel, and thus resulting in different multi-banded patterns.
How to express a protein with bioactivity? Why is the protein inactive?
a. Low solubility of the protein. You should fuse desired protein to a fusion partners and lower temperature.
b. Lack of essential post translational modification. You should change another expression system.
c. Incomplete folding. You should use a fusion partner and use strains with cold-adapted chaperones. Co-express with molecular chaperones at lower temperature. Monitor disulfide bond formation and allow further folding in vitro.
d. Mutations in cDNA. You should sequence plasmid before and after induction or use a recA− strain to ensure plasmid stability. Transform E. coli before each expression round.
Why are our protein products almost invisible in pipes?
Tips: Before opening the lid, we recommend to centrifuge in a small centrifuge for 20-30 seconds firstly to ensure that the contents are on the bottom of the tube. Our quality control steps ensure that the amount of protein contained in each tube is accurate, although sometimes you can’t see the protein powder, but the protein content in the tube is still very accurate.
How is the protein purified? Is the purity guaranteed?
Although we guarantee a minimum purity standard of >85%, some of the proteins we prepared have a purity of 95% or even 97%.
How should I reconstitute and store the products?
As for short-term storage or usage, please use sterile deionized water to completely reconstitute proteins to 0.1-1.0 mg/mL. Aliquot after 10-15 minutes if needed and store at 4℃.
As for long-term storage, the cytokines or recombinant proteins are recommended to add 5-50% of glycerol (final concentration) and aliquot for long-term storage at -20℃/-80℃. Our default final concentration of glycerol is 50%. Customers could use it as reference.
What types of tags do you use for fusion?
What is the impact of a given tag type and any potential biological activity of the protein?
Can you remove the endotoxin?
Can you offer aseptic manufacture processing?
How to determine species cross-reactivity of cytokines?
b. Many mouse cytokines may also have effect on human cells, however, the activity may be lower than the corresponding human cytokines.
c. One of the few human cytokines will be more active than corresponding mouse cytokines when acting on mouse cells, such as IL-7.
d. Interferon, GM-CSF, IL-3 and IL-4 and other cytokines are species-specific and almost have no activity on non-homologous cells.
e. In contrast, fibroblast growth factor (FGF) and neurotrophin are highly conserved and both have good activity on cells of different species.
What is the general preservative? Which kind of preservative do you usually add?
What is the general protectant? What kind of protectant do you usually add?
Can’t Find What You’re Looking For? We can help you source the best match or customize a recombinant protein solution for your study. Options may include species (human/mouse/rat), protein region/domain (full-length vs fragment), tag or label (His/GST/FLAG/biotin/fluorescent), expression system (E. coli/HEK293/insect), purity grade, formulation (buffer, carrier-free, glycerol-free), activity/functional validation (binding or enzymatic assays), endotoxin level (low-endotoxin for cell-based work), mutants/variants (point mutations, isoforms), and bulk or custom packaging. Click Talk to a Scientist to submit a request form, email us at support@biohippo.com, or explore our Research Services for additional support. Our team will be in contact with you shortly.
