Recombinant Burkholderia mallei UPF0060 membrane protein BMASAVP1_A1271 (BMASAVP1_A1271)

What is the complete sequence and structural information for BMASAVP1_A1271?

The BMASAVP1_A1271 protein is a full-length (1-110 amino acids) membrane protein from Burkholderia mallei. Its complete amino acid sequence is: MLSLAKIAALFVLTAVAEIVGCYLPWLVLKAGKPAWLLAPAALSLALFAWLLTLHPAAAARTYAAYGGVYIAVALAWLRIVDGVPLSRWDVAGAALALAGMSVIALQPRG . Structurally, it belongs to the UPF0060 protein family, which typically consists of membrane-associated proteins with characteristic hydrophobic regions. Bioinformatic analysis suggests the presence of transmembrane domains, consistent with its membrane localization. For structural studies, researchers should consider both detergent-based extraction methods and membrane mimetic systems for protein stabilization during characterization.

How should BMASAVP1_A1271 protein be properly stored and reconstituted?

The recombinant BMASAVP1_A1271 protein is typically supplied as a lyophilized powder. For optimal stability:

• Store the lyophilized protein at -20°C/-80°C upon receipt

• Avoid repeated freeze-thaw cycles by preparing working aliquots

• Working aliquots can be stored at 4°C for up to one week

For reconstitution:

• Briefly centrifuge the vial prior to opening

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

• Add glycerol to a final concentration of 5-50% (50% is recommended) for long-term storage at -20°C/-80°C

Membrane proteins require special handling during reconstitution to maintain their native conformation. Consider using mild detergents or lipid-based systems to preserve structural integrity if functional studies are planned.

How should experiments be designed to study BMASAVP1_A1271 membrane localization?

When designing experiments to study membrane localization of BMASAVP1_A1271, researchers should implement a multi-technique approach:

• Fractionation studies: Employ differential centrifugation to separate membrane fractions from bacterial cells expressing the protein, followed by Western blot analysis using anti-His antibodies (1:1,000 dilution) .

• Fluorescence microscopy: Create fluorescent protein fusions (C-terminal fusions may be preferable to avoid interfering with membrane insertion) and examine localization patterns.

• Membrane extraction analysis: Use differential solubilization with detergents of varying strengths to determine membrane association characteristics.

Your experimental design should include proper independent variables (e.g., expression conditions, cell types) and dependent variables (e.g., localization pattern, extraction efficiency), with appropriate replication (minimum three independent experiments) .

What controls are essential when working with His-tagged BMASAVP1_A1271 protein?

When working with His-tagged BMASAVP1_A1271, rigorous controls are essential for reliable interpretation:

• Negative controls:

  • Empty vector expression system

  • Unrelated His-tagged protein expressed under identical conditions

  • Western blot using secondary antibody only (to assess non-specific binding)

• Positive controls:

  • Commercial His-tagged protein standard

  • Well-characterized His-tagged membrane protein

• Experimental controls:

  • Non-tagged version of BMASAVP1_A1271 (to assess tag interference)

  • Protease digestion controls (to confirm integrity and specificity)

  • Denatured vs. native protein samples (for structural studies)

For immunodetection, use mouse monoclonal antibody against His-tag (1:1,000 dilution) followed by goat anti-mouse IgG peroxidase conjugate (1:5,000 dilution) . Always include calibration standards when performing quantitative analysis and validate antibody specificity before proceeding with complex experiments.

What expression systems are optimal for producing functional BMASAVP1_A1271?

Basic approach (for beginners):

• Use E. coli BL21(DE3) with IPTG induction

• Express at lower temperatures (16-25°C) to improve folding

• Supplement with glucose to reduce leaky expression

Advanced approach (for experienced researchers):

• Consider specialized E. coli strains (C41/C43) designed for membrane protein expression

• Evaluate membrane-targeted expression systems like MISTIC or pBAD

• For difficult cases, explore eukaryotic systems (insect cells, yeast) which may better accommodate membrane protein folding

Expression outcomes can be significantly affected by growth conditions. Design your expression experiments with systematic variation of:

• Induction timing (OD600 0.4-1.0)

• Inducer concentration (0.1-1.0 mM IPTG)

• Post-induction temperature (16-37°C)

• Media composition (standard LB vs. enriched media)

Maintain detailed records of expression conditions using standardized data tables to facilitate reproducibility and optimization.

How can I optimize purification of His-tagged BMASAVP1_A1271?

Purification of membrane proteins like BMASAVP1_A1271 presents unique challenges. A systematic approach includes:

• Membrane preparation:

  • Harvest cells by centrifugation (5,000×g, 15 min, 4°C)

  • Resuspend in lysis buffer containing protease inhibitors

  • Disrupt cells via sonication or French press

  • Remove debris by centrifugation (10,000×g, 20 min, 4°C)

  • Collect membranes by ultracentrifugation (100,000×g, 1 hour, 4°C)

• Solubilization optimization:

  • Screen detergents (DDM, LDAO, OG, etc.) at various concentrations

  • Incubate solubilized fraction with Ni-NTA resin (2-4 hours or overnight at 4°C)

• Purification:

  • Wash extensively to remove non-specific binding proteins

  • Elute with imidazole gradient (50-300 mM)

  • Assess purity by SDS-PAGE with expected molecular weight ~13 kDa plus tag

For highest purity, consider secondary purification steps such as size exclusion chromatography. The purified protein should achieve >90% purity as determined by SDS-PAGE . Detergent exchange may be necessary for downstream applications, particularly if functional studies are planned.

How can BMASAVP1_A1271 be utilized in immunological studies?

BMASAVP1_A1271 has significant potential in immunological research, particularly for understanding host-pathogen interactions involving Burkholderia mallei:

Basic applications:

• Development of detection antibodies for diagnostics

• Studying immune recognition of bacterial membrane components

Advanced applications:

• Comparative immunogenicity studies with other Burkholderia membrane proteins

• Investigation of host immune response to membrane proteins during infection

Methodology for developing immunoassays could follow protocols similar to those used for other Burkholderia membrane proteins:

• Immunize rabbits with 200 μg purified recombinant BMASAVP1_A1271 via intramuscular injection at 0 and 4 weeks

• Test antiserum reactivity against the protein and whole-cell lysates

• For cross-reactivity studies, test against related Burkholderia species

Similar studies with OmpA and flagellin (FliC) have demonstrated improved vaccine potential against B. pseudomallei , suggesting membrane proteins like BMASAVP1_A1271 may have comparable research applications.

What analytical techniques are most informative for studying BMASAVP1_A1271 function?

To comprehensively study BMASAVP1_A1271 function, multiple analytical approaches should be employed:

• Binding interaction studies:

  • Surface Plasmon Resonance (SPR)

  • Isothermal Titration Calorimetry (ITC)

  • Pull-down assays with potential interacting partners

• Structural analysis:

  • Circular Dichroism (CD) spectroscopy for secondary structure

  • Nuclear Magnetic Resonance (NMR) for detailed structure in membrane mimetics

  • Cryo-EM for membrane-embedded visualization

• Functional assays:

  • Liposome reconstitution for transport studies

  • Bacterial mutant complementation

  • Membrane integrity assessment in expression systems

When designing these experiments, follow established guidelines for experimental design , ensuring proper controls, randomization, and statistical analysis. For functional studies involving complex datasets, implement analysis approaches similar to those used in other protein studies, such as the integrated analysis methods described for BAP1 protein research .

How can BMASAVP1_A1271 contribute to understanding Burkholderia mallei pathogenesis?

As a membrane protein, BMASAVP1_A1271 may play critical roles in bacterial physiology and host interaction. Advanced research directions include:

• Host-pathogen interaction studies:

  • Investigate whether BMASAVP1_A1271 interacts with host immune receptors

  • Evaluate its role in bacterial adhesion to host cells

  • Determine if it's recognized by patient antisera (similar to testing with melioidosis goat serum at 1:100 dilution as done for other Burkholderia proteins)

• Comparative genomics approach:

  • Compare BMASAVP1_A1271 conservation across Burkholderia species

  • Identify structural homologs in other bacterial pathogens

  • Correlate sequence variations with virulence characteristics

• Loss-of-function studies:

  • Generate knockdown or knockout strains

  • Assess impact on bacterial fitness, membrane integrity, and virulence

  • Complement mutants with wild-type or modified versions

These approaches require advanced molecular biology techniques and appropriate biosafety measures given B. mallei's status as a potential bioterrorism agent. Researchers should design comprehensive experimental plans with appropriate controls and validation methods at each step.

What troubleshooting approaches are recommended when working with BMASAVP1_A1271?

When encountering challenges with BMASAVP1_A1271 research, systematic troubleshooting is essential:

Expression problems:

• Low expression yield

  • Decrease induction temperature to 16°C

  • Optimize codon usage for expression host

  • Test different E. coli strains (BL21, C41/C43, Rosetta)

  • Consider adding fusion partners (MBP, SUMO) to enhance solubility

• Protein degradation

  • Include protease inhibitors throughout purification

  • Minimize processing time and maintain consistent cold temperature

  • Add stabilizing agents (glycerol, specific lipids)

Functional characterization issues:

• Poor antibody recognition

  • Generate antibodies against multiple epitopes

  • Use both N and C-terminal tags for detection redundancy

  • Validate antibody specificity with peptide competition assays

• Inconsistent activity results

  • Standardize protein:lipid ratios in reconstitution experiments

  • Control detergent concentration precisely

  • Implement more rigorous quality control for each protein batch

When designing troubleshooting experiments, maintain proper experimental design principles with appropriate controls . Document all variations in protocols using standardized data tables to facilitate comparison and reproducibility .