SPCC663.08c Antibody

What is SPCC663.08c and why is it significant in S. pombe research?

SPCC663.08c refers to a specific gene in Schizosaccharomyces pombe (fission yeast) that encodes a protein known as Sup11p. This protein shows significant homology to Saccharomyces cerevisiae Kre9, which is involved in β-1,6-glucan synthesis. Importantly, Sup11p plays an essential role in β-1,6-glucan formation in the cell wall structure of S. pombe. Studies indicate that when sup11+ expression is reduced, β-1,6-glucan becomes absent from the cell wall, demonstrating the protein's crucial function in maintaining cell wall integrity .

The significance of SPCC663.08c extends beyond cell wall composition, as it is indispensable for proper septum assembly during cell division. Research has demonstrated that deficiency in sup11+ expression leads to severe morphological defects and malformation of the septum with massive accumulation of cell wall material, particularly β-1,3-glucan deposits which are normally restricted to the primary septum . These characteristics make SPCC663.08c/Sup11p an important target for studying fundamental cellular processes in fission yeast.

What are the technical specifications of commercially available SPCC663.08c antibodies?

Commercially available SPCC663.08c antibodies are typically polyclonal antibodies raised in rabbits. According to product specifications, these antibodies are generated using recombinant Schizosaccharomyces pombe (strain 972/ATCC 24843) SPCC663.08c protein as the immunogen . The antibodies are affinity-purified to ensure specificity and are supplied in liquid form with the following characteristics:

• Uniprot reference number: Q7Z9I3

• Isotype: IgG

• Clonality: Polyclonal

• Storage buffer: Contains 0.03% Proclin 300 as a preservative, with 50% Glycerol and 0.01M PBS at pH 7.4

• Validated applications: ELISA and Western Blot (WB)

• Species reactivity: Specifically designed for Schizosaccharomyces pombe (strain 972/ATCC 24843)

It's important to note that these antibodies are intended for research use only and not for diagnostic or therapeutic applications.

What are the optimal storage conditions for maintaining SPCC663.08c antibody activity?

To maintain optimal activity of SPCC663.08c antibodies, proper storage conditions are essential. According to manufacturer specifications, these antibodies should be stored at either -20°C or -80°C immediately upon receipt . Repeated freeze-thaw cycles should be strictly avoided as they can lead to protein denaturation, aggregation, and subsequent loss of antibody activity.

For working dilutions, it is advisable to prepare only the amount needed for immediate use. If storing diluted antibody is necessary, add carrier proteins (such as BSA at 1-5mg/ml) to minimize loss of activity. The antibody formulation typically includes 50% glycerol, which helps maintain stability during freezing and prevents complete freezing at -20°C, reducing damage from ice crystal formation .

When handling the antibody, ensure all equipment is clean and free from contaminants, particularly proteases and bacteria that could degrade the antibody. Always use sterile pipette tips and microcentrifuge tubes when aliquoting to prevent contamination.

How should researchers optimize SPCC663.08c antibody use in Western blot applications?

When optimizing SPCC663.08c antibody for Western blot applications, researchers should consider several methodological factors. First, protein extraction from fission yeast requires special attention due to the robust cell wall. Effective protocols typically include spheroplasting of S. pombe cells using enzymatic digestion with zymolyase or lysing enzymes . This step is crucial for efficient protein release and should be performed in buffers containing protease inhibitors to prevent protein degradation.

For optimal results, consider the following protocol adjustments:

• Sample preparation: After spheroplasting, use a lysis buffer compatible with membrane proteins (containing 1% Triton X-100 or NP-40) since SPCC663.08c/Sup11p is associated with cell wall synthesis .

• Gel selection: Use 10-12% polyacrylamide gels as SPCC663.08c/Sup11p has a predicted molecular weight in the mid-range protein size.

• Transfer conditions: Optimize for hydrophobic proteins with methanol concentration adjustments in the transfer buffer (10-20%).

• Blocking: 5% non-fat dry milk in TBST is typically effective, but for phospho-specific detection, BSA may be preferable.

• Antibody dilution: Start with a 1:1000 dilution of the primary antibody and adjust based on signal intensity and background levels.

• Detection: For low abundance proteins like SPCC663.08c/Sup11p, enhanced chemiluminescence (ECL) or fluorescent secondary antibodies may provide better sensitivity.

• Controls: Always include a positive control (S. pombe wild-type extract) and a negative control (sup11 deletion or knockdown strain, if viable) to validate specificity .

What approaches can researchers use to investigate SPCC663.08c/Sup11p localization in S. pombe cells?

Investigating the subcellular localization of SPCC663.08c/Sup11p in S. pombe requires careful experimental design due to the protein's association with the cell wall and potential involvement in secretory pathway compartments. Based on its homology to S. cerevisiae Kre proteins that localize throughout the secretory pathway from the endoplasmic reticulum (ER) to the plasma membrane , several methodological approaches can be employed:

• Immunofluorescence microscopy:

  • Fix cells using formaldehyde (typically 3.7-4%) combined with glutaraldehyde (0.2-0.5%) to preserve cell wall structures.

  • Perform cell wall digestion with zymolyase to create spheroplasts, allowing antibody penetration.

  • Use detergent permeabilization (0.1% Triton X-100) carefully optimized to maintain cell morphology.

  • Apply the SPCC663.08c antibody at optimized dilutions (typically starting at 1:100).

  • Use fluorophore-conjugated secondary antibodies and include DAPI staining to visualize nuclei.

• Subcellular fractionation:

  • Separate cellular components through differential centrifugation.

  • Analyze fractions via Western blotting using the SPCC663.08c antibody.

  • Include markers for different cellular compartments (ER, Golgi, plasma membrane) to identify the localization pattern.

• Epitope tagging complementary approach:

  • Generate strains expressing tagged versions of SPCC663.08c/Sup11p (e.g., GFP, mCherry).

  • Compare localization patterns between antibody staining and fluorescent protein visualization to validate findings.

  • Ensure the tag doesn't interfere with protein function by conducting functional assays .

How can researchers effectively use SPCC663.08c antibodies to study protein-protein interactions?

To study protein-protein interactions involving SPCC663.08c/Sup11p, researchers can employ several methodological approaches, each with specific optimization requirements for fission yeast systems:

• Co-immunoprecipitation (Co-IP):

  • Perform cell lysis under gentle conditions to preserve protein-protein interactions (use buffers containing 0.5-1% NP-40 or Triton X-100).

  • Optimize crosslinking conditions if interactions are transient (0.5-1% formaldehyde for 10-15 minutes).

  • Pre-clear lysates with Protein A/G beads to reduce non-specific binding.

  • Incubate cleared lysates with SPCC663.08c antibody (typically 2-5 μg per mg of protein).

  • Analyze precipitated complexes by Western blotting or mass spectrometry.

• Proximity-dependent biotin identification (BioID):

  • Generate strains expressing SPCC663.08c/Sup11p fused to a biotin ligase (BirA*).

  • Allow in vivo biotinylation of proximal proteins.

  • Purify biotinylated proteins using streptavidin beads.

  • Identify interaction partners by mass spectrometry.

• Yeast two-hybrid screening:

  • Use SPCC663.08c/Sup11p domains as bait to screen for interacting proteins.

  • Validate positive interactions by reciprocal testing and secondary methods.

• Analysis of protein complexes:

  • Employ blue native PAGE to preserve native protein complexes.

  • Use the SPCC663.08c antibody for Western blot detection following native separation.

  • Consider size-exclusion chromatography to isolate intact complexes prior to immunodetection.

When interpreting results, researchers should be aware that SPCC663.08c/Sup11p likely interacts with enzymes involved in glucan synthesis and processing, as suggested by its role in β-1,6-glucan formation and septum assembly . Verification of novel interactions should include testing the effects of sup11+ repression on the localization and function of potential interacting partners.

How can computational approaches enhance SPCC663.08c antibody design and application?

• Structure prediction:

  • If the 3D structure of SPCC663.08c antibody is unavailable, use the RosettaAntibody server to generate structural models based on the antibody sequence.

  • The process involves homology template searching for framework regions and CDR loops, followed by optimization of side chains and CDR orientations .

• Antibody-antigen binding prediction:

  • Implement two-step docking protocols to predict binding poses between the antibody and SPCC663.08c protein.

  • Begin with ClusPro for global docking to identify potential binding interfaces.

  • Refine results using SnugDock, which allows flexibility of interfacial side chains and CDR loops to generate more accurate binding models .

• Epitope optimization:

  • Perform in silico alanine scanning to identify hotspots (key residues) in the antibody-antigen interface.

  • This computational approach mutates interface residues to alanine and calculates energy changes to identify critical binding residues .

• Affinity maturation:

  • Implement computational affinity maturation protocols to design antibody variants with improved binding properties.

  • Using Rosetta-based scoring functions, generate mutations that theoretically enhance affinity and stability compared to the original antibody .

These computational approaches can guide experimental design by identifying optimal epitopes for antibody generation, predicting cross-reactivity with related proteins, and suggesting modifications to improve antibody performance. When applied to SPCC663.08c antibodies, these methods are particularly valuable for targeting specific functional domains of the protein, such as regions involved in β-1,6-glucan synthesis or septum formation .

What methodological approaches can address challenges in detecting post-translationally modified SPCC663.08c protein?

Detecting post-translationally modified SPCC663.08c/Sup11p presents unique challenges, particularly given evidence that this protein undergoes complex glycosylation patterns in S. pombe. Research indicates that Sup11p:HA can be hypo-mannosylated when expressed in an O-mannosylation mutant background and can be N-glycosylated on an unusual N-X-A sequon located within a S/T-rich region . To effectively study these modifications, researchers should consider the following methodological approaches:

• Enzymatic deglycosylation assays:

  • Treat protein samples with endoglycosidases (EndoH, PNGase F) to remove N-linked glycans.

  • Use O-glycosidases to remove O-linked mannose residues.

  • Compare migration patterns on Western blots before and after treatment to assess glycosylation status.

• Lectin affinity approaches:

  • Use lectin affinity chromatography (with ConA for mannose-rich glycans) to enrich glycosylated forms.

  • Perform lectin blotting as a complement to Western blotting to detect glycosylated proteins.

• Mass spectrometry analysis:

  • Implement specialized glycoproteomics workflows, including enrichment of glycopeptides.

  • Use electron transfer dissociation (ETD) or electron capture dissociation (ECD) for fragmenting glycopeptides while preserving modification sites.

  • Analyze data with software capable of identifying complex glycan structures.

• Epitope-specific antibody strategies:

  • Develop separate antibodies targeting glycosylated and non-glycosylated epitopes.

  • Generate antibodies against synthetic glycopeptides mimicking specific glycoforms of SPCC663.08c/Sup11p.

• Genetic approaches:

  • Express SPCC663.08c/Sup11p in various glycosylation pathway mutants (similar to the O-mannosylation mutant studies) .

  • Compare protein behavior and antibody recognition across these genetic backgrounds.

When designing experiments, researchers should consider that the unusual N-X-A sequon in SPCC663.08c/Sup11p is normally masked by O-mannosylation in wild-type cells, becoming accessible for N-glycosylation only under specific conditions . This competition between different types of glycosylation may affect antibody recognition and should be accounted for when interpreting experimental results.

How can researchers investigate the relationship between SPCC663.08c/Sup11p function and cell wall integrity pathways?

Investigating the relationship between SPCC663.08c/Sup11p function and cell wall integrity pathways requires integrated experimental approaches that address both genetic and biochemical aspects. Since sup11+ depletion leads to significant cell wall remodeling and affects β-1,6-glucan formation , the following methodological strategies are recommended:

• Genetic interaction analysis:

  • Construct double mutants between sup11+ conditional alleles and genes involved in cell wall integrity pathways.

  • Perform synthetic genetic array (SGA) analysis to systematically identify genetic interactions.

  • Analyze epistatic relationships by comparing single and double mutant phenotypes.

• Cell wall composition analysis:

  • Fractionate cell wall components using alkali and acid extractions.

  • Quantify β-1,3-glucan, β-1,6-glucan, and mannan content using specific enzymatic digestions and colorimetric or HPLC-based detection methods.

  • Compare wild-type cells with sup11+ depleted cells to identify specific changes in polysaccharide composition .

• Stress response assays:

  • Expose cells to cell wall stressors (Calcofluor White, Congo Red, SDS) and measure growth inhibition.

  • Monitor activation of cell wall integrity MAPK pathways using phospho-specific antibodies.

  • Analyze transcriptional responses to cell wall stress in wild-type versus sup11+ depleted cells.

• Protein localization under stress:

  • Track SPCC663.08c/Sup11p localization during cell wall stress using the antibody in immunofluorescence studies.

  • Determine if stress conditions alter protein modification patterns or stability.

• Interactome analysis:

  • Perform co-immunoprecipitation with SPCC663.08c antibody under normal and stress conditions.

  • Identify differentially associated proteins that may link SPCC663.08c/Sup11p to cell wall integrity signaling.

• Cell wall biotinylation:

  • Implement cell wall biotinylation techniques to identify exposed proteins and their changes in sup11+ depleted cells .

  • Use mass spectrometry to analyze differences in the cell surface proteome.

This integrated approach will help establish the precise role of SPCC663.08c/Sup11p in maintaining cell wall integrity and clarify its position within signaling networks that respond to cell wall stress.

How should researchers interpret changes in SPCC663.08c/Sup11p expression during the cell cycle?

Interpreting changes in SPCC663.08c/Sup11p expression throughout the cell cycle requires careful experimental design and data analysis, particularly given its role in septum formation and cell wall integrity. To effectively analyze such expression patterns, researchers should consider these methodological approaches:

• Cell synchronization methods:

  • Implement nitrogen starvation-release or lactose gradient centrifugation for S. pombe synchronization.

  • Verify synchronization efficiency by monitoring septation index and cell size distribution.

  • Collect samples at defined intervals covering the entire cell cycle (typically 5-10 minute intervals).

• Expression analysis approaches:

  • Perform quantitative Western blotting using SPCC663.08c antibody with appropriate loading controls.

  • Consider implementing fluorescence time-lapse microscopy with tagged SPCC663.08c/Sup11p to track localization dynamics.

  • Use RT-qPCR to correlate protein levels with transcript abundance.

• Data normalization strategies:

  • Normalize SPCC663.08c/Sup11p protein levels to multiple loading controls (e.g., α-tubulin and PCNA).

  • For transcript analysis, use cell cycle-independent reference genes such as act1+ or cdc2+.

  • Present data as fold-change relative to G1 phase levels.

• Correlation with cell cycle markers:

  • Track established cell cycle markers simultaneously (e.g., Cdc13 for G2/M, Arp3 for cytokinesis).

  • Correlate SPCC663.08c/Sup11p expression with septum formation events using calcofluor white staining.

  • Analyze co-localization with septum formation proteins during different cell cycle stages.

• Interpretation framework:

  • Analyze expression patterns in the context of septum assembly timing.

  • Given that SPCC663.08c/Sup11p is involved in β-1,6-glucan synthesis and septum formation , peak expression would be expected to coincide with or slightly precede septum formation.

  • Compare results with known expression patterns of other cell wall synthesis proteins.

When interpreting cell cycle-dependent changes, researchers should consider that transcriptome analysis of sup11+ depleted cells shows significant regulation of several cell wall glucan modifying enzymes , suggesting complex regulatory relationships that may influence expression patterns.

What analytical approaches can identify specific cell wall defects resulting from SPCC663.08c/Sup11p dysfunction?

Identifying specific cell wall defects resulting from SPCC663.08c/Sup11p dysfunction requires multiple complementary analytical approaches. Since sup11+ depletion leads to the absence of β-1,6-glucan and accumulation of cell wall material at the septum , the following methodological strategies can effectively characterize these defects:

• Microscopic analysis:

  • Perform differential interference contrast (DIC) microscopy to assess gross morphological changes.

  • Use transmission electron microscopy (TEM) to examine cell wall ultrastructure and septum thickness.

  • Implement fluorescence microscopy with specific dyes:

    • Calcofluor White for β-1,3-glucan and chitin

    • Aniline Blue for β-1,3-glucan specifically

    • Pontamine Fast Scarlet 4B for cellulose-like polysaccharides

  • Quantify staining intensity and distribution patterns using image analysis software.

• Biochemical composition analysis:

  • Fractionate cell wall components using hot alkali extraction (separates alkali-soluble α-glucan from alkali-insoluble β-glucan).

  • Perform enzymatic digestions with specific glucanases to quantify different polysaccharide components.

  • Use HPLC or NMR for detailed structural analysis of isolated fractions.

  • Compare wild-type and mutant samples to identify specific composition changes.

• Gene expression profiling:

  • Conduct transcriptome analysis comparing wild-type and sup11+ depleted cells.

  • Focus on expression changes in cell wall synthesis and remodeling genes.

  • Validate findings with RT-qPCR for selected targets.

  • Based on previous research, analyze regulation patterns of cell wall glucan modifying enzymes, particularly Gas2p, which plays a crucial role in accumulating septum material depositions in sup11+ mutants .

• Cell wall integrity testing:

  • Measure sensitivity to cell wall-degrading enzymes (zymolyase, β-glucanase).

  • Assess resistance to cell wall-perturbing agents (Calcofluor White, Congo Red).

  • Monitor osmotic stability under hypotonic conditions.

  • Quantify cell lysis rates under different stress conditions.

• Proteomic analysis of cell wall fractions:

  • Isolate and analyze cell wall proteins using mass spectrometry.

  • Compare protein profiles between wild-type and sup11+ mutant cells.

  • Focus on changes in GPI-anchored proteins that are normally attached to β-1,6-glucan.

The combined results from these analytical approaches will provide a comprehensive characterization of the specific cell wall defects resulting from SPCC663.08c/Sup11p dysfunction.

How can researchers address weak or inconsistent signals when using SPCC663.08c antibodies?

When facing weak or inconsistent signals with SPCC663.08c antibodies, researchers should implement a systematic troubleshooting approach addressing each step of the experimental workflow:

• Sample preparation optimization:

  • Ensure complete cell lysis and protein extraction by optimizing spheroplasting conditions for S. pombe .

  • Use fresh protease inhibitor cocktails to prevent protein degradation.

  • Consider using specialized extraction buffers for membrane-associated proteins (containing 1-2% NP-40 or Triton X-100).

  • Avoid sample overheating during sonication or mechanical disruption.

• Protein denaturation and loading:

  • Test different sample denaturation conditions (varying temperatures from 65-95°C and incubation times from 5-10 minutes).

  • Optimize protein loading amounts (typically 20-50 μg total protein per lane for Western blotting).

  • Ensure complete reduction of disulfide bonds with fresh DTT or β-mercaptoethanol.

• Antibody incubation parameters:

  • Test a range of primary antibody dilutions (1:250 to 1:2000).

  • Extend primary antibody incubation time (overnight at 4°C instead of 1-2 hours at room temperature).

  • Try different blocking agents (5% milk vs. 5% BSA) to reduce background while preserving specific signals.

  • Implement a stepwise temperature reduction approach (2 hours at room temperature followed by overnight at 4°C).

• Detection system enhancement:

  • Switch to more sensitive detection methods (ECL Plus or SuperSignal West Femto for chemiluminescence).

  • Consider using HRP-polymer or biotin-streptavidin amplification systems.

  • For very low abundance proteins, try fluorescent secondary antibodies with scanning at different wavelengths.

  • Extend film exposure times or adjust imaging settings on digital systems.

• Signal enhancement strategies:

  • Implement antigen retrieval techniques for fixed samples (heat-induced epitope retrieval or enzymatic retrieval).

  • For immunofluorescence, test signal amplification methods like tyramide signal amplification (TSA).

  • Use concentration methods like immunoprecipitation before Western blotting for low-abundance proteins.

• Antibody validation and quality control:

  • Test antibody activity against a known positive control (recombinant SPCC663.08c protein).

  • Consider using a different lot or source of antibody if problems persist.

  • Perform an antibody validation experiment using a sup11+ overexpression strain.

By systematically addressing these aspects, researchers can significantly improve detection sensitivity and consistency when working with SPCC663.08c antibodies.

What strategies can resolve specificity issues with SPCC663.08c antibodies in complex samples?

Resolving specificity issues with SPCC663.08c antibodies requires implementing strategic approaches to enhance target recognition while minimizing cross-reactivity in complex S. pombe samples:

• Antibody pre-adsorption techniques:

  • Incubate the antibody with extracts from sup11Δ strains (if viable) or from closely related species.

  • Use acetone powder preparations from non-specific sources to remove cross-reactive antibodies.

  • Implement peptide competition assays using the immunizing antigen to confirm specific bands.

• Blocking optimization:

  • Test different blocking agents (milk, BSA, fish gelatin, commercial blockers) to identify optimal conditions.

  • Extend blocking time (2-4 hours) at room temperature.

  • Add 0.1-0.5% Tween-20 to reduce hydrophobic interactions.

  • Consider adding 5% normal serum from the secondary antibody species to reduce non-specific binding.

• Wash protocol enhancement:

  • Increase wash buffer stringency (higher salt concentration, 150-500 mM NaCl).

  • Add detergents like Triton X-100 (0.1-0.3%) to wash buffers.

  • Extend washing times and increase the number of wash steps.

  • Use continuous agitation during washing steps.

• Affinity purification of antibodies:

  • Perform affinity purification against the specific immunogen.

  • Consider sequential affinity purification, first depleting cross-reactive antibodies then enriching specific ones.

  • Use antigen-coupled columns for highly specific antibody isolation.

• Validation with additional techniques:

  • Compare results with epitope-tagged SPCC663.08c/Sup11p detection.

  • Perform siRNA or genetic knockdown of SPCC663.08c/Sup11p to verify band disappearance.

  • Use mass spectrometry to confirm the identity of detected bands.

• Sample complexity reduction:

  • Implement subcellular fractionation to enrich for compartments where SPCC663.08c/Sup11p is expected (e.g., membrane fractions).

  • Use size exclusion or ion exchange chromatography as pre-purification steps.

  • For immunoprecipitation, employ more stringent wash conditions to reduce non-specific binding.

By combining these methodological approaches, researchers can significantly improve the specificity of SPCC663.08c antibody detection in complex S. pombe samples, leading to more reliable experimental outcomes.

Table 1: SPCC663.08c Antibody Technical Specifications

Table 2: Recommended Experimental Conditions for SPCC663.08c Antibody Applications

Table 3: Cell Wall Analysis Methods for SPCC663.08c/Sup11p Research