Anti-Caspr2/CNTNAP2 Antibody Picoband®

Overview

Anti-Caspr2/CNTNAP2 Antibody Picoband® is an antibody reagent for detection of CNTNAP2 (protein inhibitor of activated STAT 3). Researchers commonly use anti-CNTNAP2 antibodies to measure relative expression and localization across biological samples, with assay selection guided by the listed applications (WB, IHC, Flow, ELISA).

Boster Bio Anti-Caspr2/CNTNAP2 Antibody Picoband® catalog # A02819-2. Tested in ELISA, WB applications. This antibody reacts with Human, Mouse, Rat. The brand Picoband indicates this is a premium antibody that guarantees superior quality, high affinity, and strong signals with minimal background in Western blot applications. Only our best-performing antibodies are designated as Picoband, ensuring unmatched performance.

Key elements and design rationale

• Target: CNTNAP2 — Potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 2 (protein inhibitor of activated STAT 3). Alternative names: E3 SUMO-protein ligase PIAS3; Protein inhibitor of activated STAT protein 3; PIAS3
• Antibody format: Polyclonal; Rabbit IgG
• Species context: Host: Rabbit, Reactivity: Human,Mouse,Rat
• Purification: Immunogen affinity purified.
• Immunogen: E.coli-derived human Caspr2/CNTNAP2 recombinant protein (Position: N363-E1159).
• Molecular weight context: observed 170 kDa, calculated 96950 MW (reported)
• Provided application(s): WB, IHC, Flow, ELISA

These attributes help contextualize how the antibody is commonly selected (host/clonality/isotype/label) and how signals are interpreted across sample types and assay formats.

Biological background

Function: Functions as an E3-type small ubiquitin-like modifier (SUMO) ligase, stabilizing the interaction between UBE2I and the substrate, and as a SUMO-tethering factor. Plays a crucial role as a transcriptional coregulation in various cellular pathways, including the STAT pathway and the steroid hormone signaling pathway. Involved in regulating STAT3 signaling via inhibiting STAT3 DNA-binding and suppressing cell growth. Enhances the sumoylation of MTA1 and may participate in its paralog-selective sumoylation (PubMed:21965678, PubMed:9388184). Sumoylates CCAR2 which promotes its interaction with SIRT1 (PubMed:25406032). Diminishes the sumoylation of ZFHX3 by preventing the colocalization of ZFHX3 with SUMO1 in the nucleus (PubMed:24651376).

Cellular localization: Cytoplasm.

Tissue details: Widely expressed.

Background: Contactin-associated protein-like 2 is a protein that in humans is encoded by the CNTNAP2 gene. This gene encodes a member of the neurexin family which functions in the vertebrate nervous system as cell adhesion molecules and receptors. This protein, like other neurexin proteins, contains epidermal growth factor repeats and laminin G domains. In addition, it includes an F5/8 type C domain, discoidin/neuropilin- and fibrinogen-like domains, thrombospondin N-terminal-like domains and a putative PDZ binding site. This protein is localized at the juxtaparanodes of myelinated axons, and mediates interactions between neurons and glia during nervous system development and is also involved in localization of potassium channels within differentiating axons. This gene encompasses almost 1.5% of chromosome 7 and is one of the largest genes in the human genome. It is ly bound and regulated by forkhead box protein P2, a transcription factor related to speech and language development. This gene has been implicated in multiple neurodevelopmental disorders, including Gilles de la Tourette syndrome, schizophrenia, epilepsy, autism, ADHD and intellectual disability.

Cross reactivity: No cross-reactivity with other proteins.

Research relevance and current trends

• Quantitative and spatial profiling: expression patterns are increasingly studied across cell states using multiplex imaging and omics-informed validation.
• Isoforms and post-translational modifications: researchers often evaluate how isoform composition and PTMs can shift apparent molecular weight or localization.
• Context-aware interpretation: comparative studies commonly include perturbations (stimulation, inhibition, genetic models) to relate target changes to pathway behavior.

Common research applications

• Western blot (WB): compare relative target abundance and apparent size shifts (e.g., isoforms/PTMs) across conditions.
• Immunohistochemistry (IHC): assess distribution across tissue compartments and compare staining patterns between groups.
• Flow cytometry: quantify target-positive populations and compare shifts after stimulation or differentiation.

Across these uses, researchers typically interpret changes in signal as relative differences between matched sample groups, considering sample preparation and biological context.

Notes for experimental interpretation

• Apparent molecular weight can vary due to isoforms, proteolysis, glycosylation, phosphorylation, and sample preparation differences.
• Species reactivity and epitope conservation can influence observed signal patterns, especially in cross-species studies.
• Control concepts: include appropriate negative controls (e.g., isotype controls where relevant) and, when feasible, genetic or orthogonal controls (KO/KD, peptide competition, or independent assays) to support interpretation.

For antibody reagents, monoclonal antibodies are often chosen for epitope consistency across lots, while polyclonals may recognize multiple epitopes and can show different background characteristics depending on context.

Customization & Add-ons: Can’t find the antibody you need—or require a custom format for your assay? We can help you source the best match or support custom antibody solutions for diverse research needs, including species and isotype selection, conjugations and labeling (e.g., HRP/AP, biotin, fluorophores), purification grade options (Protein A/G, affinity purified), formulation preferences (buffer selection, carrier-free, glycerol-free), custom concentrations and aliquoting, low-endotoxin options for cell-based work, and application-focused QC/validation support (project dependent). Click Talk to a Scientist to submit a request, email us at support@biohippo.com, or explore our Research Services for additional support—our team will follow up with feasibility details and next steps.