BETV4

What is BETV4 and what are its primary biological functions?

BETV4 is a calcium-binding protein of 2-EF-hand type primarily expressed in mature birch (Betula verrucosa) pollen. It functions as an allergen, causing allergic reactions in humans, and exists in pollen of various plant species. Due to its cross-reactivity, BETV4 serves as a marker allergen for plant polysensitization .

It's important to note that literature contains some inconsistency regarding BETV4's identity. While some sources describe it as a pollen allergen , others characterize it as a member of the BET (bromodomain and extra-terminal) family of proteins involved in gene regulation and transcriptional control . This FAQ focuses primarily on BETV4 as the pollen allergen.

How is recombinant BETV4 produced for research applications?

Recombinant BETV4 for research is typically produced in Sf9 insect cells as a glycosylated polypeptide chain with a calculated molecular mass of 10,473 Dalton. The protein is expressed with a 6xHis tag at the N-terminus to facilitate purification through proprietary chromatographic techniques. The final product is supplied as a sterile filtered clear solution in 20mM HEPES buffer (pH 7.9) containing 6M Urea .

What storage and stability considerations are critical for BETV4 experiments?

For optimal experimental results, researchers should follow these stability guidelines:

Proper storage conditions are critical to maintaining the protein's immunological functions, including its ability to bind IgE-type human antibodies .

What analytical techniques provide the most reliable detection of BETV4 in experimental systems?

Several analytical techniques have been validated for BETV4 research:

When using antibody-based detection, the BETV4 polyclonal antibody (PACO50214) has been validated for Western blotting and ELISA applications. This antibody is raised against recombinant Betula pendula Polcalcin Bet v 4 protein (amino acids 1-85) and purified using Protein G to >95% purity .

How can researchers optimize experimental design when studying BETV4's role in allergic responses?

While specific experimental designs for BETV4 aren't explicitly described in the literature, researchers can apply Bayesian optimal experimental design principles to maximize information gained from BETV4 studies. These approaches include:

• Implementing search algorithms from artificial intelligence that efficiently explore possible design parameters

• Utilizing sampling procedures to evaluate design parameter combinations more efficiently

• Collecting data across different experimental designs to compare their ability to discriminate among competing models of BETV4 function

These computational improvements make experimental procedures more tractable and can significantly reduce the amount of data required to distinguish between behavioral models of allergic responses to BETV4.

What are the primary methodological challenges in transcriptomic analysis of BETV4 expression?

Transcriptomic analysis of BETV4 expression requires careful consideration of several methodological challenges:

• Sequence processing and assembly can be performed using tools like 454 Newbler with default parameters (40 bp overlap and 90% identity)

• Translation frame assessment should be conducted through BLASTx searches against relevant databases

• Proper annotation requires tools such as InterProScan and Gene Ontology terms

• To identify differential gene expression between samples, contigs should be clustered using applications like CD-Hit 454 (90% similarity) to eliminate redundant sequences

• Statistical analysis must employ appropriate normalization methods and linear regression models based on Gaussian distribution

Researchers should ensure they include only contigs with a minimum threshold of mapped reads (e.g., eight or more) and apply appropriate false discovery rate controls.

How does BETV4 contribute to cross-reactivity patterns in allergy diagnostics?

BETV4's calcium-binding structure makes it an important marker for cross-reactivity studies. As a polcalcin present in various plant pollens, it can help identify patients with polysensitization patterns. When designing cross-reactivity studies, researchers should:

• Incorporate BETV4 in multiplex testing panels alongside other calcium-binding pollen allergens

• Apply cluster analysis to identify patterns of sensitization across patient populations

• Consider BETV4 as a potential marker when investigating patients with multiple plant allergies

Understanding these cross-reactivity patterns has significant implications for both diagnosis and immunotherapy approaches.

What role does BETV4 play in atopic dermatitis research?

Cluster analysis of molecular components in patients with atopic dermatitis has shown that sensitization to molecular allergens is a significant factor. While specific percentages for BETV4 sensitization aren't provided in the available research, studies indicate that sensitization to molecular fungal allergens was recorded in 58% of atopic dermatitis patients .

Researchers investigating BETV4's role in atopic dermatitis should consider:

• Using ISAC Multiplex testing to simultaneously assess sensitization to multiple allergens including BETV4

• Applying cluster analysis to identify patterns of sensitization

• Correlating BETV4 sensitization with clinical manifestations of atopic dermatitis

How can immunological assays for BETV4 be validated for research applications?

Validation of immunological assays for BETV4 should include:

• Confirmation of binding to IgE-type human antibodies

• Verification through immunodot tests with both positive and negative sera panels

• Assessment of specificity through cross-reactivity testing with related allergens

• Evaluation of sensitivity using standardized allergen preparations

Researchers should document purification methods, storage conditions, and quality control metrics when reporting results from BETV4 immunological assays.

How does the molecular structure of BETV4 relate to its allergenicity?

BETV4 is a calcium-binding protein featuring a 2-EF-hand structural motif. The EF-hand domains consist of helix-loop-helix structures that bind calcium ions. These structural features are critical to understanding BETV4's:

• Ability to bind calcium ions, which may affect protein conformation

• Interaction with IgE antibodies from allergic patients

• Cross-reactivity with similar calcium-binding proteins from other plant species

• Stability under different experimental conditions

Structural studies of BETV4 are essential for developing targeted therapeutic approaches for birch pollen allergies.

What approaches can be used to compare BETV4 across different plant species?

To conduct comparative studies of BETV4 across plant species, researchers should consider:

• Sequence alignment analysis to identify conserved domains and variable regions

• Recombinant expression of BETV4 homologs from different species for functional comparison

• Structural analysis of calcium-binding domains across species

• Immunological cross-reactivity testing using patient sera

• Transcriptomic profiling to compare expression patterns in different plant species and tissues

These comparative approaches can help identify conserved allergenicity determinants and species-specific variations that might affect diagnosis and treatment.

What considerations are important when designing antibodies for BETV4 research?

When designing antibodies for BETV4 research, several factors are critical:

Researchers should validate antibody performance in their specific experimental systems before proceeding with large-scale studies .

How might optimal experimental design improve BETV4 allergy research?

Applying optimal experimental design principles to BETV4 research offers several advantages:

• More efficient exploration of experimental design parameters through AI-based search algorithms

• Reduced data requirements for model discrimination through Bayesian optimization approaches

• Improved ability to dynamically optimize online experiments

• Enhanced capability to test competing hypotheses about BETV4's role in allergic responses

What transcriptomic approaches show promise for understanding BETV4 expression?

Advanced transcriptomic approaches that could enhance BETV4 expression research include:

• Deep sequencing with proper removal of ribosomal, mitochondrial, and chloroplast reads

• Assembly of sequences using tools like 454 Newbler 2.6 with appropriate overlap and identity parameters

• Translation frame assessment using BLASTx searches against Swiss-Prot

• Annotation with InterProScan and Gene Ontology terms

• Differential expression analysis using normalized read counts and appropriate statistical models

These methodologies can provide deeper insights into the regulation of BETV4 expression across different plant tissues and environmental conditions.

How might BETV4 research inform broader allergen immunotherapy approaches?

Understanding BETV4's molecular characteristics and cross-reactivity patterns has important implications for allergen immunotherapy:

• Its role as a marker allergen for plant polysensitization could help identify patients who might benefit from specific immunotherapy approaches

• Structural studies could inform the design of hypoallergenic variants for safer immunotherapy

• Cross-reactivity patterns might explain clinical responses to immunotherapy targeting related allergens

• Comparative studies across plant species could help develop broader-spectrum immunotherapy approaches

Research in this area requires careful integration of molecular, immunological, and clinical data to translate findings into improved patient care.