The SPBC336.13c Antibody (Uniprot No. Q9UST2) is a custom antibody product developed for research applications, specifically targeting proteins in Schizosaccharomyces pombe (fission yeast), strain 972/ATCC 24843. It is listed in commercial catalogs as part of a collection of rare antibodies for specialized studies . The antibody is supplied in a 2 mL or 0.1 mL volume, with no explicit details on its isotype, epitope specificity, or recommended applications in the provided sources .
SPBC336.13c was utilized in a study on isotopic labeling for structural analysis of bispecific antibodies (BsAbs) . Researchers incorporated 13C-labeling into half-antibodies using E. coli fermentation, achieving >99% incorporation efficiency. The antibody was assembled into a hybrid bispecific construct (hBsAb) to enable mass spectrometry (MS)-based characterization of individual heavy/light chain pairs .
| Parameter | Value |
|---|---|
| 13C-Incorporation (hole-hAb) | 99.1% |
| Molecular Weight (hBsAb) | 145,217 Da |
| Mass Shift Due to Labeling | 3178 Da |
Bispecific antibodies like SPBC336.13c derivatives are being explored for cancer immunotherapy, targeting tumor-associated antigens while engaging immune cells . Their modular design allows simultaneous binding to multiple epitopes, enhancing therapeutic efficacy .
Production Limitations: E. coli-derived antibodies lack post-translational modifications (e.g., glycans), which may affect functionality in therapeutic contexts .
Cost and Scalability: The 8x higher production cost compared to standard IgG antibodies highlights economic barriers for large-scale use .
KEGG: spo:SPBC336.13c
STRING: 4896.SPBC336.13c.1
SPBC336.13c refers to a specific gene/protein in Schizosaccharomyces pombe, designated by its systematic name in the S. pombe genome database. Fission yeast serves as an excellent model organism for studying fundamental cellular processes due to its relatively simple genome and its conservation of many key cellular mechanisms found in higher eukaryotes. When investigating SPBC336.13c, researchers typically utilize techniques like protein isolation, Western blotting, and immunofluorescence to understand its function within cellular networks. Research efforts often focus on this protein in the context of stress response pathways or cellular aging mechanisms, as these are well-established research areas using fission yeast as a model organism .
To validate SPBC336.13c antibody specificity, researchers should implement multiple complementary approaches. Begin with Western blot analysis using wild-type fission yeast lysates compared against a knockout or knockdown strain lacking SPBC336.13c expression. A specific antibody will show band presence in wild-type samples and absence/reduction in knockout samples. Additionally, perform immunoprecipitation followed by mass spectrometry to confirm the antibody is capturing the intended target. For further validation, conduct immunofluorescence microscopy with appropriate controls, including competitive blocking with purified antigen and secondary-only controls. Cross-reactivity testing against related proteins should also be performed, especially when conducting network analysis studies where multiple related proteins may be present .
For optimal maintenance of SPBC336.13c antibody activity, proper storage and handling are essential. Store antibody aliquots at -20°C for long-term preservation, while avoiding repeated freeze-thaw cycles by preparing small working aliquots (50-100 μl). For short-term storage (1-2 weeks), keep at 4°C with appropriate preservatives. When handling, maintain sterile conditions and avoid contamination with microorganisms. Prior to use, centrifuge briefly to collect liquid at the bottom of the vial. For dilutions, use high-quality buffers (typically PBS or TBS with 0.1% BSA). Document all usage, including freeze-thaw cycles, dilution factors, and experimental conditions to track antibody performance over time. Commercial SPBC336.13c antibodies are typically supplied in 2ml/0.1ml sizes, which should be handled according to the manufacturer's specific recommendations .
For optimal Western blotting with SPBC336.13c antibody, begin with proper sample preparation by lysing S. pombe cells using glass bead disruption in a buffer containing protease inhibitors, followed by clarification through centrifugation. Load 20-30 μg of total protein per lane on a 10-12% SDS-PAGE gel, then transfer to PVDF or nitrocellulose membrane at 100V for 60-90 minutes in Tris-glycine buffer with 20% methanol. Block membranes with 5% non-fat milk or BSA in TBST for 1 hour at room temperature. Dilute SPBC336.13c antibody to 1:1000-1:5000 in blocking buffer and incubate overnight at 4°C with gentle agitation. After washing with TBST (3 × 10 minutes), apply HRP-conjugated secondary antibody (1:5000-1:10000) for 1 hour at room temperature. Develop using ECL reagent and optimize exposure times based on signal intensity. Include positive controls (purified protein or overexpression lysate) and negative controls (knockout strain) to validate specificity .
For effective immunoprecipitation of SPBC336.13c from fission yeast extracts, prepare cell lysates under native conditions using a gentle lysis buffer (typically 50 mM Tris-HCl pH 7.5, 150 mM NaCl, 0.1% NP-40, protease inhibitors) with glass bead disruption at 4°C. Clear lysates by centrifugation (13,000g, 15 minutes, 4°C) and pre-clear with Protein A/G beads for 1 hour to reduce non-specific binding. Incubate 1-5 mg of total protein with 2-5 μg of SPBC336.13c antibody overnight at 4°C with gentle rotation. Add 30-50 μl of pre-equilibrated Protein A/G beads and continue incubation for 2-3 hours. Perform stringent washes (at least 4) with lysis buffer, followed by elution with SDS sample buffer or by competition with excess antigen peptide. For co-immunoprecipitation studies aimed at identifying interaction partners within protein networks, consider using milder wash conditions to preserve weaker interactions. Always run parallel controls with non-specific IgG and input samples to assess specificity and efficiency .
For effective immunofluorescence microscopy using SPBC336.13c antibody in fission yeast, begin with proper cell fixation by treating exponentially growing cells with 3.7% formaldehyde for 30 minutes at the growth temperature. After washing with PEM buffer (100 mM PIPES pH 6.9, 1 mM EGTA, 1 mM MgSO4), digest cell walls with Zymolyase (1 mg/ml) or Lysing Enzymes (5 mg/ml) in PEMS buffer (PEM + 1.2 M sorbitol) for 30-60 minutes at 37°C. Permeabilize cells with 1% Triton X-100 in PEM for 5 minutes, then block with PEMBAL (PEM + 1% BSA, 0.1% sodium azide, 100 mM lysine hydrochloride) for 30 minutes. Incubate with SPBC336.13c primary antibody (1:100-1:500 dilution) overnight at 4°C, wash 3 times with PEMBAL, then apply fluorophore-conjugated secondary antibody (1:500) for 2 hours at room temperature. Include DAPI (5 μg/ml) to visualize nuclei and mount cells in antifade mounting medium. For optimal results, include wild-type and knockout controls, and consider double labeling with markers for specific cellular compartments to determine precise subcellular localization .
For ChIP-seq experiments using SPBC336.13c antibody, begin with chromatin preparation by crosslinking exponentially growing S. pombe cells with 1% formaldehyde for 15 minutes at room temperature, followed by quenching with 125 mM glycine. Lyse cells using glass bead disruption in lysis buffer containing protease inhibitors, followed by sonication to generate 200-500 bp DNA fragments (verify sizes by gel electrophoresis). Pre-clear chromatin with Protein A/G beads and normal IgG for 2 hours. For immunoprecipitation, incubate 100-500 μg of chromatin with 5-10 μg of SPBC336.13c antibody overnight at 4°C, then add Protein A/G beads for 2-4 hours. Perform sequential washes with increasingly stringent buffers (low salt, high salt, LiCl, and TE). Elute protein-DNA complexes and reverse crosslinks by incubating at 65°C overnight. Treat samples with RNase A and Proteinase K, then purify DNA using phenol-chloroform extraction or column purification. Prepare sequencing libraries according to your sequencing platform's protocols, incorporating appropriate controls (input chromatin, IgG, and if available, a SPBC336.13c knockout strain). After sequencing, align reads to the S. pombe genome and identify enriched regions using peak-calling algorithms like MACS2, followed by motif analysis to identify consensus binding sequences .
For optimal protein complex purification using SPBC336.13c antibody for mass spectrometry, implement a multi-step strategy beginning with careful experimental design. Grow S. pombe cultures in synthetic minimal medium to minimize contamination with medium components. Harvest cells during mid-log phase and lyse gently using a physiological buffer (50 mM HEPES pH 7.5, 100 mM KCl, 2.5 mM MgCl2, 0.1% NP-40, protease inhibitors, phosphatase inhibitors) with glass bead disruption. Clarify lysates by sequential centrifugation steps (13,000g followed by 100,000g). Perform immunoprecipitation by incubating 10-20 mg of lysate with SPBC336.13c antibody cross-linked to Protein A/G beads (using dimethyl pimelimidate) to prevent antibody contamination in the final sample. After binding overnight at 4°C, wash extensively with lysis buffer, followed by detergent-free buffer washes. Elute complexes using either competitive elution with antigenic peptide or gentle acid elution (100 mM glycine pH 2.5, neutralized immediately). For quantitative proteomics, consider SILAC or TMT labeling to distinguish specific interactions from background. Process samples for mass spectrometry with minimal sample handling, using filter-aided sample preparation (FASP) or in-solution digestion with sequencing-grade trypsin. Analyze samples using LC-MS/MS and identify proteins with appropriate database search algorithms, followed by filtering against CRAPome or similar databases to remove common contaminants .
To combine isotope labeling with SPBC336.13c antibody techniques for quantitative proteomics, several sophisticated approaches can be implemented. Begin by cultivating S. pombe strains in SILAC (Stable Isotope Labeling with Amino acids in Cell culture) media containing either light (natural) or heavy (13C6, 15N2-lysine and 13C6, 15N4-arginine) amino acids for at least 8 doubling times to ensure >98% incorporation. For comparing experimental conditions, use "heavy" labeling for experimental conditions and "light" for controls, or implement a triple-SILAC approach (light, medium, heavy) for comparing multiple conditions simultaneously. Prepare cell lysates under native conditions to preserve protein interactions, and perform immunoprecipitation with SPBC336.13c antibody. After IP, mix equal amounts of heavy and light samples to minimize processing variation. Process for mass spectrometry using in-solution digestion with LysC and trypsin, followed by peptide fractionation with high-pH reversed-phase chromatography. Analyze using high-resolution LC-MS/MS, implementing MS1-based quantification for SILAC pairs or MS2-based quantification for TMT-labeled samples. For absolute quantification, consider using isotope-labeled reference peptides specific to SPBC336.13c. In data analysis, calculate heavy/light ratios to determine relative abundance changes, applying appropriate statistical tests and false discovery rate controls. This approach allows precise quantification of SPBC336.13c interaction partners and posttranslational modifications under different experimental conditions .
Common specificity issues with SPBC336.13c antibody include cross-reactivity with similar proteins, high background signal, and batch-to-batch variability. To address these challenges, implement a comprehensive validation strategy. First, perform epitope mapping to identify the specific region of SPBC336.13c recognized by the antibody, and conduct in silico analysis to identify potential cross-reactive proteins with similar epitopes. Test the antibody against recombinant SPBC336.13c protein and lysates from knockout strains to confirm specificity. For high background issues, optimize blocking conditions (test BSA vs. milk, different concentrations, and blocking times) and increase washing stringency (higher salt concentration or mild detergents). To reduce non-specific binding, pre-adsorb the antibody with acetone powder prepared from a SPBC336.13c knockout strain. For batch-to-batch variability, maintain a reference stock of a well-characterized lot and test each new lot against this standard using identical samples and protocols. Consider developing a monoclonal antibody if polyclonal variability is problematic. When analyzing Western blot data, verify that the observed molecular weight matches the predicted size of SPBC336.13c (accounting for potential post-translational modifications), and confirm band identity using mass spectrometry if possible .
When facing contradictory results between different SPBC336.13c antibody detection methods, implement a systematic troubleshooting approach. First, evaluate each method's technical parameters: for Western blots, verify protein denaturation conditions, as some epitopes may be destroyed or exposed differently under various denaturation protocols; for immunofluorescence, compare different fixation methods (formaldehyde, methanol, or combinations) as they preserve different cellular structures and epitopes; for immunoprecipitation, test different lysis conditions that may preserve or disrupt protein complexes. Next, consider epitope accessibility issues—the antibody may recognize exposed epitopes in one technique but not in others where the epitope is masked by protein folding, interactions, or post-translational modifications. Perform epitope mapping to determine which region of SPBC336.13c the antibody recognizes and how this might affect detection in different contexts. Use multiple antibodies targeting different epitopes of SPBC336.13c to confirm results. For definitive validation, employ orthogonal techniques such as mass spectrometry for protein identification, or utilize genetically tagged versions of SPBC336.13c (GFP-tag, HA-tag) and compare results using tag-specific antibodies. Finally, integrate data from multiple experimental approaches including functional assays to build a coherent model of SPBC336.13c behavior that accommodates seemingly contradictory observations .
For analyzing co-localization data from SPBC336.13c antibody immunofluorescence experiments, implement rigorous statistical approaches rather than relying on visual assessment alone. Begin with high-quality image acquisition using confocal microscopy with appropriate controls for bleed-through and chromatic aberration. Process images with minimal manipulation, applying only uniform adjustments across all experimental conditions. For quantitative co-localization analysis, calculate Pearson's correlation coefficient (PCC) and Mander's overlap coefficients (MOC) using software such as ImageJ with the JACoP plugin or CellProfiler. PCC values range from -1 (perfect negative correlation) to +1 (perfect positive correlation), with values >0.5 generally indicating significant co-localization. For more sophisticated analysis, implement object-based approaches that identify discrete structures in each channel and measure their spatial relationships. Use intensity correlation analysis (ICA) to determine if the intensities of two fluorophores vary together. For statistical validation, analyze at least 30-50 cells per condition across 3-5 biological replicates. Apply appropriate statistical tests (t-test for two conditions, ANOVA for multiple conditions) to determine if co-localization coefficients differ significantly between experimental groups. Consider employing machine learning approaches for automated segmentation and classification when analyzing large datasets. Always include randomized controls (generated by rotating or flipping one channel) to establish baseline co-localization values expected by chance .
To incorporate SPBC336.13c antibody data into protein-protein interaction (PPI) networks, implement a multi-layered integration strategy. Begin by performing immunoprecipitation coupled with mass spectrometry (IP-MS) using SPBC336.13c antibody under various physiological conditions (normal growth, stress response, cell cycle stages) to identify interaction partners. Apply stringent filtering using appropriate statistical methods (e.g., SAINT algorithm) to distinguish true interactions from background, and validate key interactions through reciprocal IP or proximity labeling techniques (BioID, APEX). Convert interaction data into a network format using platforms like Cytoscape, assigning confidence scores based on detection frequency, abundance, and validation status. Integrate this experimental network with existing S. pombe PPI databases such as BioGRID or STRING, resolving contradictions through weighting schemes that prioritize direct experimental evidence. Enhance network context by incorporating functional data (GO annotations), expression correlation data, and genetic interaction profiles. Apply network analysis algorithms to identify functional modules, calculate topological parameters (degree, betweenness centrality), and predict the functional importance of SPBC336.13c within the network. For dynamic network analysis, integrate time-series data to observe how SPBC336.13c interactions change during processes like stress response or cell cycle progression. This integrated approach allows researchers to position SPBC336.13c within its biological context and generate testable hypotheses about its functions and regulatory relationships .
For studying stress response networks using SPBC336.13c antibody in fission yeast, implement a multi-faceted approach that captures both spatial and temporal dynamics. Begin with time-course experiments exposing S. pombe cultures to relevant stressors (oxidative, heat, osmotic, nutritional) and collect samples at strategic timepoints (early: 0-15 minutes; middle: 30-60 minutes; late: 2-4 hours). For each timepoint, perform quantitative Western blotting with SPBC336.13c antibody to track expression changes, immunofluorescence to monitor subcellular localization shifts, and chromatin immunoprecipitation followed by sequencing (ChIP-seq) if SPBC336.13c has DNA-binding properties. Complement these approaches with proximity-based labeling techniques (BioID, APEX) to capture transient stress-induced interaction partners. For network construction, integrate these temporal profiles with transcriptome data (RNA-seq) and parallel measurements of other network components. Apply dimensionality reduction techniques (PCA, t-SNE) to identify patterns in the multi-parameter datasets, and use computational modeling approaches like ordinary differential equations (ODEs) or Boolean networks to describe system dynamics. Validate model predictions through targeted perturbation experiments, such as analyzing stress response in SPBC336.13c mutants with altered expression or phosphorylation sites. This comprehensive approach allows mapping of SPBC336.13c's position and dynamics within stress response networks, identifying both upstream regulators and downstream effectors, and characterizing feedback mechanisms that may be critical for stress adaptation in fission yeast .
To integrate genetic interaction data with SPBC336.13c antibody-based proteomics for improved functional prediction, implement a systematic framework that leverages complementary data types. Start by collecting comprehensive genetic interaction profiles for SPBC336.13c through systematic deletion library screens, identifying both negative (synthetic sickness/lethality) and positive (suppression/epistasis) genetic interactions. In parallel, perform quantitative proteomics experiments using SPBC336.13c antibody for immunoprecipitation followed by mass spectrometry under identical conditions to the genetic screens. Generate high-confidence physical and genetic interaction networks centered on SPBC336.13c, then apply network alignment algorithms to identify overlaps and discrepancies between these networks. Genes/proteins appearing in both networks often represent functional modules, while those unique to either network may indicate indirect regulatory relationships or compensatory pathways. Enhance this integration with additional data layers including co-expression patterns, subcellular co-localization data, and shared phenotypic signatures. Apply machine learning approaches such as random forests or support vector machines to predict functional annotations based on the integrated network features, using established Gene Ontology terms as training data. Validate predictions experimentally through targeted assays focusing on the most confident predictions. This integrative approach significantly improves functional prediction accuracy by capturing complementary aspects of cellular organization—physical interactions reveal direct mechanistic relationships, while genetic interactions capture functional compensation and pathway structures—providing a more complete understanding of SPBC336.13c's biological roles in fission yeast cellular processes .