Recombinant Mouse Alpha-2B adrenergic receptor (Adra2b)

How does mouse Adra2b compare with human ADRA2B homolog?

The human ADRA2B and mouse Adra2b share high sequence homology but have distinct differences:

While both proteins function as alpha-2 adrenergic receptors, human ADRA2B has been more extensively studied for its association with conditions such as decreased basal metabolic rate in obese subjects, enhanced emotional memory, and familial epilepsy . Mouse models expressing Adra2b are valuable for comparative studies to understand receptor function across species and provide insights into human disease mechanisms .

What expression systems are optimal for producing recombinant Mouse Adra2b protein?

While multiple expression systems can be used for recombinant Mouse Adra2b production, each offers distinct advantages:

According to the available product information, recombinant full-length Mouse Alpha-2B adrenergic receptor has been successfully expressed in E. coli with an N-terminal His tag . For functional studies requiring proper post-translational modifications, mammalian expression systems may be preferable, though E. coli-expressed protein is suitable for structural studies, antibody production, and certain binding assays .

What are the critical considerations for maintaining stability of recombinant Adra2b during storage and handling?

Maintaining stability of recombinant Mouse Adra2b is critical for experimental reproducibility. Key considerations include:

• Storage conditions: Store at -20°C/-80°C upon receipt, with aliquoting recommended to avoid repeated freeze-thaw cycles .

• Buffer composition: Use Tris/PBS-based buffers with approximately 6% Trehalose at pH 8.0 for optimal stability .

• Reconstitution protocol:

  • Briefly centrifuge the vial before opening

  • Reconstitute in deionized sterile water to 0.1-1.0 mg/mL

  • Add glycerol to 5-50% final concentration for long-term storage

  • The standard 50% glycerol concentration provides optimal stability

• Working conditions: Store working aliquots at 4°C for up to one week; repeated freeze-thaw cycles should be strictly avoided .

• Lyophilization: The protein is typically supplied as a lyophilized powder, which enhances long-term stability prior to reconstitution .

What detection methods are most suitable for Mouse Adra2b research?

Multiple detection approaches can be employed depending on the research question:

Current recombinant Mouse Adra2b products have been validated for SDS-PAGE applications, with purity typically greater than 90% . For human ADRA2B, flow cytometry has been successfully employed using specific antibodies to detect the protein in transfected cells , suggesting similar approaches could be adapted for mouse Adra2b.

How can researchers effectively use ELISA for quantitative measurement of Mouse Adra2b?

ELISA provides a sensitive method for quantitative measurement of Mouse Adra2b in various sample types:

• Sample preparation:

  • Suitable for tissue homogenates, cell lysates, and biological fluids

  • Samples must be diluted to fall within the mid-range of the assay (typically 0.156-10 ng/ml)

• Assay considerations:

  • Colorimetric detection methods are commonly employed

  • Lyophilized standards are used for calibration curves

  • Optimize sample dilutions to ensure readings fall within the linear range

• Performance factors:

  • Temperature and incubation time consistency is critical

  • Operation procedures and lab conditions should be strictly controlled

  • Ideally, the entire assay should be performed by the same researcher to minimize variation

• Limitations:

  • ELISA kits are typically optimized for detection of native proteins

  • Detection of recombinant proteins may be challenging due to potential differences in sequence or tertiary structure

  • Specific validation is required when using recombinant proteins as standards

What signaling pathways are associated with Mouse Adra2b and how can they be studied?

Mouse Adra2b, like other α2-adrenergic receptors, plays critical roles in regulating neurotransmitter release from sympathetic nerves and adrenergic neurons in the central nervous system . Key signaling pathways include:

• G-protein coupled signaling:

  • Primarily couples to inhibitory G proteins (Gi/Go)

  • Leads to inhibition of adenylyl cyclase and reduction in cAMP levels

  • Results in decreased protein kinase A (PKA) activity

• Translational regulation:

  • Adra2b associates with eIF-2B, a guanine nucleotide exchange protein

  • This interaction influences regulation of protein translation

  • May explain some of the receptor's broader cellular effects

• Experimental approaches for studying signaling:

  • cAMP assays to measure changes in second messenger levels

  • Calcium mobilization assays for intracellular Ca2+ dynamics

  • Receptor internalization and trafficking studies using fluorescently-tagged receptors

  • Phosphorylation studies to assess receptor desensitization

What are the challenges associated with antibody validation for Adra2b research?

Antibody validation is critical for generating reliable data in Adra2b research:

• Specificity validation approaches:

  • Testing on tissues or cell lines known to express or not express Adra2b

  • Using knockout/knockdown models as negative controls

  • Comparing multiple antibodies targeting different epitopes

• Common challenges:

  • Cross-reactivity with other alpha-2 adrenergic receptor subtypes due to high sequence homology

  • Conformational epitopes may be affected by sample preparation methods

  • Limited availability of validated antibodies for mouse Adra2b specifically

• Validation strategies for flow cytometry applications:

  • Use transfected cell lines expressing Adra2b alongside control transfections

  • Employ appropriate controls to set quadrant markers based on control antibody staining

  • Validate staining protocols for membrane-associated proteins specifically

• Performance characterization:

  • Determine optimal dilutions for each application empirically

  • Validate antibody performance in the specific experimental conditions

  • Consider generating custom antibodies if commercially available options are inadequate

How do antagonists interact with Mouse Adra2b compared to other adrenergic receptor subtypes?

Understanding antagonist profiles is crucial for pharmacological manipulation of Adra2b:

The rank order for antagonist affinity is: yohimbine > chlorpromazine > phentolamine > mianserine > spiperone > prazosin > alprenolol > propanolol > pindolol . This profile helps researchers select appropriate compounds for receptor blockade in experimental settings, with yohimbine being the preferred antagonist for selective Adra2b inhibition.

What functional differences exist between mouse Adra2b deletion variants and how do they compare to human polymorphisms?

While the search results don't specifically detail mouse Adra2b deletion variants, research on human ADRA2B variants provides comparative insights:

• Human ADRA2B polymorphic variants:

  • A deletion variant has decreased G protein-coupled receptor kinase-mediated phosphorylation

  • This results in reduced receptor desensitization

  • Associated with reduced basal metabolic rate in obese subjects

  • May contribute to obesity pathogenesis

  • Related to enhanced emotional memory and increased focus on negative aspects of situations

• Research implications:

  • Mouse models expressing human variant forms can help elucidate mechanisms

  • Comparative studies between mouse and human variants can reveal species-specific differences in receptor function

  • Understanding these variations is critical when translating findings from mouse models to human applications

• Experimental design considerations:

  • Genotyping is essential when using primary cells or tissues

  • Recombinant expression should specify the variant being used

  • Functional studies should account for potential variant-specific differences in signaling

What strategies can address poor expression or solubility of recombinant Mouse Adra2b?

Membrane proteins like Adra2b often present expression and solubility challenges:

• Optimization of expression conditions:

  • Modify induction parameters (temperature, inducer concentration, duration)

  • Test different E. coli strains designed for membrane protein expression

  • Consider codon optimization for the expression host

• Fusion partners and solubility tags:

  • N-terminal His-tags have been successfully used

  • Consider larger solubility-enhancing tags (MBP, SUMO, etc.)

  • Test different tag positions (N-terminal vs. C-terminal)

• Detergent screening:

  • Systematic testing of different detergent classes

  • Optimize detergent concentration for extraction

  • Consider detergent mixtures or addition of lipids

• Alternative expression systems:

  • If E. coli yields poor results, consider insect or mammalian cells

  • Cell-free expression systems can sometimes overcome difficulties with toxic membrane proteins

How can researchers optimize storage conditions to prevent activity loss of Adra2b preparations?

Maintaining Adra2b activity requires careful attention to storage conditions:

• Stability assessment:

  • Activity loss should be less than 5% within the expiration period under appropriate storage

  • Regular quality control testing is recommended for long-term studies

• Optimal storage recommendations:

  • Store at -20°C to -80°C for long-term storage

  • Aliquot to avoid repeated freeze-thaw cycles

  • For working stocks, store at 4°C for maximum of one week

• Buffer optimization:

  • Tris/PBS-based buffers with 6% Trehalose at pH 8.0 enhance stability

  • Addition of glycerol (5-50% final concentration) improves freeze-thaw resistance

  • Consider adding protease inhibitors for sensitive preparations

• Reconstitution best practices:

  • Centrifuge vials before opening

  • Use deionized sterile water for reconstitution

  • Prepare at concentrations between 0.1-1.0 mg/mL

  • Standardize reconstitution protocols to ensure consistency