CHST13 Antibody

What is CHST13 and what biological functions does it serve?

CHST13, also known as C4ST3 (carbohydrate chondroitin 4 sulfotransferase 13), belongs to the sulfotransferase 2 family and plays a critical role in glycosaminoglycan modification. The protein catalyzes the transfer of sulfate to position 4 of the N-acetylgalactosamine (GalNAc) residue of chondroitin . Chondroitin sulfate constitutes the predominant proteoglycan in cartilage and is distributed on many cell surfaces. Beyond its structural role, CHST13 is involved in various cellular processes including cell adhesion and migration . Recent research has unexpectedly implicated CHST13 in immune response regulation, particularly in the context of vaccine responsiveness .

What are the molecular characteristics of human CHST13 protein?

Human CHST13 has a calculated molecular weight of 39 kDa, though interestingly, the observed molecular weight in experimental conditions is typically around 25 kDa . This discrepancy likely reflects post-translational modifications or proteolytic processing. The gene is identified under GenBank Accession Number NM_152889, with the NCBI Gene ID 166012 and UniProt ID Q8NET6 . The protein contains domains characteristic of sulfotransferases and functions primarily within the Golgi apparatus where glycosaminoglycan modification occurs.

What types of CHST13 antibodies are available for research applications?

Commercially available CHST13 antibodies include polyclonal antibodies raised in rabbits, such as the 20141-1-AP antibody and PACO02575 . These antibodies are typically generated using synthetic peptides derived from the internal region of human CHST13 as immunogens . Both unconjugated forms for standard applications and potentially conjugated versions for specialized detection methods may be available. For most research applications, affinity-purified antibodies are recommended to minimize background and ensure specific detection.

What validation data should researchers review before selecting a CHST13 antibody?

Researchers should examine:

• Species reactivity profile (confirmed reactivity with human, mouse, and rat samples for some antibodies)

• Application validation data (Western blot images, IHC staining patterns)

• Positive control tissues (e.g., mouse liver for WB and IP; human kidney and hepatocirrhosis tissue for IHC)

• Observed molecular weight compared to theoretical weight

• Cross-reactivity testing with related sulfotransferases

The discrepancy between calculated (39 kDa) and observed (25 kDa) molecular weights is particularly important to note when evaluating Western blot results.

What are the validated applications for CHST13 antibodies?

CHST13 antibodies have been validated for multiple experimental applications, including:

Positive detection has been confirmed in specific sample types for each application, providing researchers with confidence regarding appropriate experimental models .

What are the recommended dilutions and protocols for Western blot applications?

For Western blot applications, the recommended dilution range is typically 1:500-1:2000 . The optimal protocol includes:

• Sample preparation: Total protein extraction from tissues (mouse liver shows good expression) or cells

• Protein separation: SDS-PAGE with appropriate percentage acrylamide gel (10-12% recommended)

• Transfer: Standard semi-dry or wet transfer to PVDF or nitrocellulose membrane

• Blocking: 5% non-fat milk or BSA in TBST for 1 hour at room temperature

• Primary antibody incubation: CHST13 antibody diluted 1:500-1:2000 in blocking buffer, overnight at 4°C

• Detection: Appropriate HRP-conjugated secondary antibody and ECL detection system

Researchers should expect to observe a band at approximately 25 kDa, rather than the calculated 39 kDa .

What are the optimal conditions for immunohistochemistry with CHST13 antibodies?

For IHC applications, CHST13 antibodies are typically used at dilutions ranging from 1:20-1:200 or 1:100-1:300 . The recommended protocol includes:

• Tissue preparation: Formalin-fixed, paraffin-embedded sections (5 μm thickness)

• Antigen retrieval: TE buffer pH 9.0 (preferred) or citrate buffer pH 6.0 as an alternative

• Blocking: Appropriate serum blocking (e.g., 10% normal goat serum)

• Primary antibody: CHST13 antibody at recommended dilution, overnight at 4°C

• Detection: Polymer-based detection system with appropriate chromogen

Human kidney and hepatocirrhosis tissues have been validated as positive controls for IHC applications .

How is CHST13 involved in immune response regulation and vaccine efficacy?

Recent integrative genomic analysis identified CHST13 as one of 20 genes that contribute to differential immune responses to seasonal influenza vaccination . The study combined genetic, transcriptional, and immunologic data in humans, revealing that CHST13 is among a group of genes potentially involved in intracellular antigen transport and processing . Remarkably, many of the identified genes encode proteins with general roles in membrane trafficking and intracellular transport rather than specific immune functions.

This discovery suggests that CHST13 and its genetic variants may influence vaccine immunogenicity through mechanisms related to antigen processing and presentation. The findings open new avenues for vaccine development, suggesting that targeting proteins like CHST13 could enhance vaccine efficacy, particularly in individuals who typically show poor response to standard vaccination protocols .

What approaches can be used to study CHST13 genetic variation and its impact on immune response?

Based on the integrative genomic study methodology , researchers can investigate CHST13 genetic variation using:

• Genotyping: Genome-wide SNP analysis focusing on the CHST13 locus and surrounding regions

• Transcriptional profiling: Measuring CHST13 expression levels before and after immune stimulation

• eQTL analysis: Identifying SNPs associated with differential CHST13 expression

• Correlation analysis: Associating CHST13 expression patterns with antibody response magnitude

• Causal modeling: Determining whether genotype associations with antibody responses are mediated by CHST13 expression

These approaches can help identify functional CHST13 variants that may serve as biomarkers for vaccine response prediction or targets for enhancing immune responses .

How can CHST13 antibodies be used in studies of glycosaminoglycan sulfation?

CHST13 antibodies can facilitate research on chondroitin sulfation patterns through:

• Co-localization studies: Combining CHST13 immunofluorescence with glycosaminoglycan-specific stains

• Enzymatic activity correlation: Relating CHST13 protein levels with sulfotransferase activity measurements

• Subcellular localization: Determining the precise Golgi compartment where CHST13 functions

• Knockdown/knockout validation: Confirming antibody specificity and studying functional outcomes of CHST13 depletion

• Protein-protein interaction studies: Identifying CHST13 binding partners in the sulfation machinery

These approaches can provide insights into the regulation of glycosaminoglycan structure and function in both normal physiology and disease states.

What are common issues when using CHST13 antibodies and how can they be resolved?

Common challenges and solutions include:

• Multiple bands in Western blot:

  • Verify sample preparation (complete denaturation)

  • Optimize primary antibody dilution (start with 1:1000)

  • Increase blocking stringency

  • Consider post-translational modifications or isoforms

• Weak signal in IHC/IF:

  • Optimize antigen retrieval (try both TE buffer pH 9.0 and citrate buffer pH 6.0)

  • Increase antibody concentration (1:20-1:50 range for weak signals)

  • Extend primary antibody incubation time

  • Use signal amplification systems

• High background in IF/ICC:

  • Increase blocking time and concentration

  • Optimize antibody dilution (start with 1:50)

  • Include additional wash steps

  • Use immunoglobulin blocking if working with Fc receptor-expressing cells

What positive and negative controls are recommended for CHST13 antibody validation?

Recommended controls include:

Positive tissue controls:

• Western blot and IP: Mouse liver tissue

• IHC: Human kidney tissue and human hepatocirrhosis tissue

• IF/ICC: HeLa cells

Negative controls:

• Primary antibody omission

• Pre-absorption with immunizing peptide

• CHST13 knockdown/knockout samples (gold standard)

• Isotype control antibody at equivalent concentration

Always include both positive and negative controls in experimental design to ensure valid interpretation of results.

What are the optimal storage conditions for CHST13 antibodies?

CHST13 antibodies should be stored at -20°C for long-term stability . The typical formulation includes PBS with 0.02% sodium azide and 50% glycerol at pH 7.3 . Under these conditions, the antibodies remain stable for at least one year after shipment. Aliquoting is generally unnecessary for -20°C storage of the standard formulation, though small aliquots may be prepared to avoid repeated freeze-thaw cycles for frequently used antibodies .

Some preparations may contain small amounts of BSA (0.1%) for additional stability . As with all antibodies, avoid repeated freeze-thaw cycles and exposure to light, and follow manufacturer-specific recommendations for each product.