Recombinant Populus trichocarpa CASP-like protein POPTRDRAFT_788163 (POPTRDRAFT_788163)

What is Recombinant Populus trichocarpa CASP-like protein POPTRDRAFT_788163?

Recombinant Populus trichocarpa CASP-like protein POPTRDRAFT_788163 is a full-length protein consisting of 169 amino acids derived from the Western balsam poplar (Populus trichocarpa, also known as Populus balsamifera subsp. trichocarpa) . The protein is recombinantly expressed in E. coli with an N-terminal His-tag to facilitate purification and detection . This protein is also known by several alternative names, including CASP-like protein 4D1 and PtCASPL4D1, and is identified in databases with the UniProt ID B9NBE5 .

The protein is supplied as a lyophilized powder with purity greater than 90% as determined by SDS-PAGE analysis . While specific functional characteristics are not detailed in the available literature, as a member of the CASP-like protein family, it may share structural or functional similarities with other CASP proteins, which are often associated with Casparian strip formation in plants.

How should POPTRDRAFT_788163 be stored for optimal stability?

Proper storage of POPTRDRAFT_788163 is critical for maintaining its structural integrity and functional properties. According to product specifications, researchers should adhere to the following storage guidelines:

The protein is typically supplied as a lyophilized powder, which provides better stability during shipping and long-term storage . Researchers should aliquot the reconstituted protein to minimize the number of freeze-thaw cycles, as repeated freezing and thawing can lead to protein denaturation, aggregation, and loss of activity . The addition of cryoprotectants such as glycerol (recommended at 50% final concentration) can help maintain protein stability during freezing .

What expression systems are used for producing recombinant POPTRDRAFT_788163?

Based on the available information, E. coli is the primary expression system used for the production of recombinant POPTRDRAFT_788163 . The protein is expressed as a fusion protein with an N-terminal His-tag, which facilitates purification through metal affinity chromatography techniques .

E. coli expression offers several advantages for POPTRDRAFT_788163 production:

• Relatively high protein yields

• Well-established protocols and expression vectors

• Cost-effective production compared to eukaryotic systems

• Simplified purification using His-tag affinity methods

• Lack of plant-specific post-translational modifications

• Potential issues with proper folding of membrane-associated proteins

• Possible formation of inclusion bodies requiring refolding procedures

• Absence of glycosylation that might be present in the native protein

The search results do not mention alternative expression systems such as yeast, insect cells, or plant-based expression systems for this particular protein .

What are the alternative names and identifiers for POPTRDRAFT_788163?

Identifying all alternative names and database identifiers is crucial for comprehensive literature searches and database mining. POPTRDRAFT_788163 is associated with several alternative designations:

Researchers should use these multiple identifiers when conducting database searches to ensure comprehensive retrieval of relevant information. Different databases and publications may use different naming conventions, so awareness of all alternative identifiers can prevent overlooking important research findings or related protein information.

What are the optimal conditions for reconstitution of lyophilized POPTRDRAFT_788163 for functional studies?

The reconstitution of lyophilized POPTRDRAFT_788163 requires careful attention to several parameters to ensure optimal protein functionality for downstream applications. Based on the product specifications, the following protocol is recommended:

• Centrifuge the vial briefly before opening to ensure all lyophilized material is at the bottom of the tube .

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

• For long-term storage of the reconstituted protein, add glycerol to a final concentration of 5-50% (with 50% being the default recommendation) and aliquot before storing at -20°C or -80°C .

While the search results do not provide specific buffer conditions for functional studies beyond the initial reconstitution, researchers should consider optimizing the following parameters based on their specific experimental requirements:

• pH conditions (the storage buffer is at pH 8.0, which may serve as a starting point)

• Salt concentration for maintaining protein solubility

• Addition of reducing agents if disulfide bonds affect protein function

• Presence of specific cofactors or metal ions that might be required for activity

• Detergent concentration if the protein has membrane-associated domains

Optimization of these conditions would typically involve activity assays or stability tests across a range of buffer compositions.

How does the His-tag affect the functional properties of recombinant POPTRDRAFT_788163?

The recombinant POPTRDRAFT_788163 protein contains an N-terminal His-tag to facilitate purification , but researchers should carefully consider the potential impacts of this tag on protein function and structure:

Potential effects of the His-tag:

• Structural alterations: The N-terminal His-tag may influence protein folding, particularly if the N-terminus is involved in structural elements or if it is normally processed in vivo.

• Functional interference: If the N-terminal region of the native protein is involved in protein-protein interactions, substrate binding, or catalytic activity, the His-tag might sterically hinder these functions.

• Protein solubility: In some cases, the His-tag can enhance protein solubility due to the charged nature of the histidine residues, though this effect is protein-dependent.

• Oligomerization: The tag might affect protein oligomerization by interfering with interfaces involved in self-association.

Recommended experimental approaches:

For critical functional studies, researchers should consider:

• Comparing tagged and untagged versions of the protein if possible

• Using a cleavable His-tag system with a protease recognition site

• Employing alternative tag positions (C-terminal vs. N-terminal) if N-terminal tagging proves problematic

• Including appropriate controls in functional assays to account for potential tag effects

While the available literature does not provide specific data on how the His-tag affects this particular protein , awareness of these potential issues is essential for proper experimental design and data interpretation.

What experimental approaches can be used to study protein-protein interactions involving POPTRDRAFT_788163?

Investigating protein-protein interactions is crucial for understanding the functional role of POPTRDRAFT_788163 in plant biology. While the search results do not provide specific interaction data for this protein, they mention that protein interaction information for POPTRDRAFT_788163 has been detected "by several methods such as yeast two hybrid, co-IP, pull-down and so on" . Researchers can employ multiple complementary approaches:

In vitro interaction methods:

• Pull-down assays: Leveraging the His-tagged POPTRDRAFT_788163 as bait to capture interacting proteins from plant cell extracts, followed by mass spectrometry identification.

• Surface Plasmon Resonance (SPR) or Bio-Layer Interferometry (BLI): For quantitative measurement of binding kinetics between purified POPTRDRAFT_788163 and candidate interacting partners.

• Isothermal Titration Calorimetry (ITC): To determine thermodynamic parameters of protein-protein interactions.

Cell-based interaction methods:

• Yeast two-hybrid screening: Creating fusion constructs with POPTRDRAFT_788163 to systematically screen for interacting partners from Populus cDNA libraries .

• Co-immunoprecipitation: Using antibodies against POPTRDRAFT_788163 or its potential partners to isolate protein complexes from plant extracts .

• Proximity-based labeling: Using BioID or APEX2 fusions with POPTRDRAFT_788163 to identify proteins in close proximity within the cellular environment.

Visualization methods:

• Bimolecular Fluorescence Complementation (BiFC): To visualize protein interactions in plant cells.

• Förster Resonance Energy Transfer (FRET): For detecting interactions between fluorescently labeled proteins.

Each method has specific advantages and limitations, and a comprehensive protein interaction study would typically employ multiple complementary approaches for validation.

How can researchers assess the structural integrity of purified POPTRDRAFT_788163?

Assessing the structural integrity of purified POPTRDRAFT_788163 is essential for ensuring reliable and reproducible experimental results. Researchers can employ multiple analytical techniques:

Basic protein characterization:

• SDS-PAGE analysis: The product information indicates that recombinant POPTRDRAFT_788163 has purity greater than 90% as determined by SDS-PAGE . This method verifies the molecular weight and initial purity.

• Western blotting: Using antibodies against the His-tag or against POPTRDRAFT_788163 epitopes to confirm identity.

Advanced structural assessment:

• Size-exclusion chromatography: To evaluate the oligomeric state and detect protein aggregation.

• Circular dichroism (CD) spectroscopy: To analyze secondary structure content and confirm proper protein folding.

• Differential scanning fluorimetry (DSF): To assess thermal stability and identify buffer conditions that enhance protein stability.

• Limited proteolysis: To investigate the presence of well-folded domains versus flexible or unstructured regions.

Homogeneity assessment:

• Dynamic light scattering (DLS): To evaluate sample homogeneity and detect aggregation.

• Native PAGE: To assess the native state of the protein and potential oligomerization.

High-resolution analysis:

• Mass spectrometry: For accurate mass determination and verification of the complete amino acid sequence .

• Nuclear magnetic resonance (NMR) spectroscopy: For detailed structural analysis (for smaller proteins or domains).

• X-ray crystallography or cryo-electron microscopy: For high-resolution structural determination, if applicable to research goals.

For POPTRDRAFT_788163 specifically, researchers should establish baseline measurements and quality control parameters appropriate for their experimental applications.

What are the challenges in designing experiments to elucidate the biological function of POPTRDRAFT_788163 in planta?

Investigating the biological function of POPTRDRAFT_788163 in planta presents several significant challenges that researchers should consider when designing their experimental approaches:

Technical challenges:

• Transformation efficiency: Developing efficient transformation protocols for Populus species to create transgenic lines with altered POPTRDRAFT_788163 expression.

• Long generation time: Populus species have considerably longer generation times compared to model plants like Arabidopsis, extending the timeline for genetic studies.

• Genomic complexity: The poplar genome contains potential gene duplications and family members that may exhibit functional redundancy.

Biological considerations:

• Functional redundancy: As part of the CASP-like protein family, other members may compensate for altered POPTRDRAFT_788163 expression, potentially masking phenotypes.

• Tissue-specific expression: Understanding the native expression pattern is critical for targeting experiments to relevant tissues and developmental stages.

• Environmental responsiveness: Populus species respond to various environmental factors that might influence POPTRDRAFT_788163 expression or function.

Experimental design considerations:

• Appropriate controls: Experimental design must include proper controls to account for variables in plant growth, transformation methods, and protein expression levels .

• Multiple approaches: Combining reverse genetics (e.g., RNAi, CRISPR-Cas9), protein localization studies, and biochemical characterization will likely be necessary for comprehensive functional analysis.

• Model system alternatives: Using heterologous expression in model plants like Arabidopsis may provide initial functional insights while Populus transgenic lines are being developed.

• Phenotypic assays: Developing appropriate phenotypic assays that can detect subtle changes in plant development or stress responses.

The complexity of these challenges necessitates careful experimental planning and often requires multiple complementary approaches to build a comprehensive understanding of POPTRDRAFT_788163 function.

What are the best practices for designing experiments using POPTRDRAFT_788163 in different research contexts?

Effective experimental design is crucial for generating reliable and interpretable results with POPTRDRAFT_788163. Drawing from principles of experimental design in biology research , researchers should consider the following best practices:

Fundamental experimental design principles:

• Clear hypothesis formulation: Develop specific, testable hypotheses about POPTRDRAFT_788163 function or properties before designing experiments .

• Internal consistency: Ensure all experimental components (hypotheses, methods, controls, and analysis approaches) are aligned and interrelated .

• Controls: Include comprehensive controls specific to the experimental context:

  • Negative controls (buffer alone, unrelated proteins)

  • Positive controls when available

  • Tag-only controls to distinguish His-tag effects from protein-specific effects

• Replication and randomization:

  • Include both biological and technical replicates

  • Randomize experimental units when possible to minimize systematic biases

  • Determine appropriate sample sizes through power analysis

Protein-specific considerations:

• Protein quality: Verify the integrity and purity (>90% by SDS-PAGE) of each POPTRDRAFT_788163 preparation before use.

• Storage conditions: Follow recommended storage protocols (-20°C/-80°C, avoiding freeze-thaw cycles) to maintain protein functionality.

• Concentration optimization: Start with the recommended reconstitution concentration (0.1-1.0 mg/mL) but optimize for specific assays.

• Expression system limitations: Consider potential limitations of E. coli-expressed protein , such as lack of plant-specific post-translational modifications.

Context-specific design elements:

• In vitro biochemical studies: Include concentration gradients, time courses, and buffer optimization experiments.

• Cellular studies: Consider subcellular localization, protein-protein interactions, and temporal dynamics.

• In planta studies: Account for tissue specificity, developmental timing, and potential functional redundancy.

Rigorous experimental design that incorporates these principles will enhance the reliability and reproducibility of research findings with POPTRDRAFT_788163.

How should researchers present data from experiments involving POPTRDRAFT_788163 in scientific publications?

Effective presentation of experimental data is critical for communicating research findings clearly. Based on guidelines for scientific writing , researchers should follow these best practices when presenting data from POPTRDRAFT_788163 experiments:

Text organization and content:

• Logical flow: Structure the results section to guide readers through a logical progression of findings related to POPTRDRAFT_788163 .

• Precision in terminology: Reserve terms like "increased" or "decreased" for statistically significant changes only .

• Numerical precision: Maintain consistent decimal places throughout the manuscript when reporting measurements .

• Statistical reporting: Report exact p-values rather than just thresholds (e.g., p=0.032 rather than p<0.05) . For significance levels below 0.001, p<0.001 is acceptable .

• Data grouping: For complex studies, organize results under subheadings corresponding to different aspects of POPTRDRAFT_788163 characterization or function .

Table design:

Figure preparation:

• Axis labeling: Ensure clear labeling of axes, with Y-axis labels written vertically from bottom to top .

• Explanatory notes: Include comprehensive figure legends that allow understanding without referring to the main text .

• Statistical information: Indicate statistical tests used, sample sizes, and significance levels in figure legends .

• Data highlighting: Emphasize critical findings in explanatory notes to guide reader attention .

• Methodological details: Include relevant experimental details like protein concentrations, incubation times, or analytical methods in figure legends .

General considerations:

• Data presentation efficiency: Avoid repeating the same data in text, tables, and figures; choose the most appropriate format for each dataset .

• Flow diagrams: Consider using flow diagrams to illustrate complex experimental procedures for POPTRDRAFT_788163 purification or analysis .

• Focus: Present only data directly relevant to the study questions about POPTRDRAFT_788163 .

Following these guidelines will enhance the clarity and impact of research communications involving POPTRDRAFT_788163.

What statistical approaches are recommended for analyzing data from functional studies of POPTRDRAFT_788163?

Selecting appropriate statistical methods is essential for rigorous data analysis in POPTRDRAFT_788163 research. While specific analytical approaches will depend on the particular experimental design, researchers should consider the following statistical framework:

Descriptive statistics:

• Central tendency and dispersion: Report means/medians with standard deviations/interquartile ranges for all quantitative measurements of POPTRDRAFT_788163 properties .

• Graphical representation: Use appropriate visualizations (histograms, box plots, scatter plots) to illustrate data distributions.

• Precision: Maintain consistent significant figures when reporting values, typically determined by measurement precision .

Inferential statistics:

• Parametric tests:

  • Student's t-test for comparing two experimental conditions

  • ANOVA with appropriate post-hoc tests (e.g., Tukey's HSD, Bonferroni) for multiple comparisons

  • Regression analysis for dose-response relationships or kinetic studies

• Non-parametric alternatives:

  • Mann-Whitney U test or Wilcoxon signed-rank test when normality assumptions are not met

  • Kruskal-Wallis or Friedman tests for multiple non-parametric comparisons

• Statistical power considerations:

  • A priori power analysis to determine required sample sizes

  • Post hoc power analysis when interpreting negative results

Specialized analytical approaches:

• For binding studies: Non-linear regression for determining dissociation constants

• For kinetic analyses: Michaelis-Menten kinetics or other appropriate models if enzymatic activity is being studied

• For structural studies: Statistical approaches specific to the analytical technique (e.g., circular dichroism spectral analysis)

Reporting best practices:

• Transparency: Clearly describe all statistical methods used, including software packages and versions .

• Significance communication: Report exact p-values and confidence intervals rather than just significance thresholds .

• Multiple testing correction: Apply and report appropriate corrections (e.g., Bonferroni, Benjamini-Hochberg) when performing multiple comparisons.

• Effect sizes: Report effect sizes along with statistical significance to communicate biological relevance.

Researchers should select statistical approaches that are appropriate for their specific experimental design and data characteristics, ensuring alignment between the statistical methods and the research questions about POPTRDRAFT_788163.

How can researchers validate the specificity of antibodies against POPTRDRAFT_788163?

Antibody validation is critical for ensuring the reliability of immunological studies involving POPTRDRAFT_788163. A comprehensive validation strategy should include multiple complementary approaches:

Biochemical validation methods:

• Western blot analysis:

  • Comparing detection of recombinant POPTRDRAFT_788163 versus native protein

  • Testing for a single band at the expected molecular weight (~18-19 kDa for the 169 amino acid protein, plus tag size)

  • Including appropriate controls: positive (recombinant protein), negative (unrelated proteins), and specificity controls (pre-immune serum)

• Immunoprecipitation validation:

  • Confirming ability to specifically immunoprecipitate POPTRDRAFT_788163 from complex mixtures

  • Validating immunoprecipitated proteins by mass spectrometry

  • Testing reciprocal immunoprecipitation with known interaction partners

Specificity controls:

• Peptide competition assays:

  • Pre-incubating antibodies with purified POPTRDRAFT_788163 or immunizing peptides

  • Demonstrating signal reduction in Western blots or immunostaining

• Cross-reactivity assessment:

  • Testing against closely related CASP-like proteins from Populus trichocarpa

  • Evaluating species cross-reactivity if using antibodies across different plant species

Genetic validation:

• Knockout/knockdown controls:

  • Comparing antibody reactivity in wild-type versus POPTRDRAFT_788163-deficient samples

  • Using RNAi or CRISPR-engineered plant tissues with reduced target expression

Application-specific validation:

• Immunohistochemistry controls:

  • Secondary antibody-only controls

  • Pre-immune serum controls

  • Peptide competition controls

  • Known expression pattern correlations

• Immunofluorescence validation:

  • Colocalization with established markers if subcellular location is known

  • Comparison with fluorescent protein-tagged POPTRDRAFT_788163 expression

Documentation and quality control:

• Comprehensive documentation:

  • Recording all validation experiments with detailed methods

  • Maintaining images of original Western blots and other validation data

• Batch testing:

  • Validating each new antibody lot against established standards

  • Maintaining reference samples for long-term comparisons

Thorough antibody validation is essential for ensuring reproducibility and reliability of results, particularly given the potential for cross-reactivity with other CASP-like proteins in Populus trichocarpa.

What controls should be included in experiments involving recombinant POPTRDRAFT_788163?

Proper experimental controls are essential for generating reliable and interpretable data with recombinant POPTRDRAFT_788163. The following controls should be considered based on experimental context:

Protein-specific controls:

• Negative controls:

  • Buffer-only controls to account for buffer component effects

  • Heat-denatured POPTRDRAFT_788163 to distinguish between specific activity and non-specific effects

  • Irrelevant proteins of similar size/characteristics for specificity assessment

• Tag-related controls:

  • Another protein with the same His-tag to control for tag-specific effects

  • Tag-only peptides for interaction studies

  • If possible, compare tagged versus untagged versions of POPTRDRAFT_788163

• Concentration controls:

  • Concentration gradients to establish dose-dependent relationships

  • Time-course experiments to determine optimal incubation periods

Experimental context controls:

Technical and procedural controls:

• Inter-assay calibration:

  • Standard curves in each experimental run

  • Reference samples across multiple experiments

  • Internal controls for normalization

• Reagent controls:

  • Testing critical reagents from different lots or sources

  • Age-matched reagents for time-sensitive components

• Environmental controls:

  • Temperature, pH, and ionic strength monitoring

  • Controlling for light exposure if relevant

  • Standardized incubation conditions

• Sample processing controls:

  • Monitoring freeze-thaw effects by comparing fresh vs. frozen samples

  • Testing effects of different reconstitution protocols

• Statistical controls:

  • Multiple biological and technical replicates

  • Randomization of sample processing order

  • Blinding of sample identity where applicable

Implementing comprehensive controls tailored to the specific experimental questions and methods will enhance the validity and reproducibility of research involving recombinant POPTRDRAFT_788163.