APCS Antibody
Product Specs
Constituents: 50% Glycerol, 0.01M PBS, pH 7.4
Target Background
- Research suggests that the F57I mutation in lysozyme affects its aggregation process, leading to the formation of cytotoxic species. SAP has been shown to prevent cell death in flies carrying this mutation by inhibiting the accumulation of toxic F57I structures. PMID: 27428539
- Data indicate that SAP interacts with at least 33 proteins/ligands in plasma under physiological calcium levels. These ligands can be categorized into apolipoproteins, complement system proteins, coagulation proteins, and components that regulate proteolysis. PMID: 28098450
- Studies have found that adolescents with metabolic syndrome have significantly higher levels of serum haptoglobin, fetuin-A, platelet factor-4, high-sensitive C-reactive protein (hs-CRP), SAP, and alpha1-acid glycoprotein (AGP) compared to control subjects. PMID: 27754964
- Single nucleotide polymorphisms (SNPs) in APCS have been associated with a later age of onset in familial amyloid polyneuropathy. PMID: 26286643
- Evidence suggests that SAP activates CD209 DC-SIGN to regulate the innate immune system differently from C-reactive protein (CRP), and that DC-SIGN is a target for antifibrotics. PMID: 26106150
- X-ray analysis of the SAP complex with CPHPC and cadmium ions provides a more detailed understanding of the interaction than observed with calcium ions. PMID: 25084341
- In comparison to wildtype C57BL/6 mice, "SAP knock-out" (Apcs-/-) mice exhibit a more persistent inflammatory response and increased fibrosis after bleomycin treatment. PMID: 24695531
- The effects of SAP and Xiapex (Collagenase Clostridium histolyticum) on fibrocytes derived from Dupuytren's disease have been evaluated. PMID: 24933153
- Plasma protein SAP binds to FcgammaRI on monocytes to inhibit fibrocyte differentiation, and binds to FcgammaRIIa on neutrophils to reduce neutrophil adhesion. PMID: 25024390
- In the late phase post-myocardial infarct, there is a coordinated decrease in immune response-inflammation proteins, except for SAP which shows an increase related to the specific activation of the classical complement pathway. PMID: 23992930
- Nine different proteins (haptoglobin, transthyretin, apolipoprotein A-1, serum amyloid P component, apolipoprotein E, complement factor H, fibrinogen gamma, thrombin, complement C3) have been identified as a potential diagnostic pattern of Parkinson's disease. PMID: 23385359
- Human SAP binds phosphoethanolamine, while rabbits seem to have low levels of SAP that bind to a lesser extent. PMID: 23600950
- These findings indicate that SAP functions as a host defense factor, similar to other peptidoglycan recognition proteins and nucleotide-binding oligomerization domain-like receptors. PMID: 23966633
- SAP may act as an effective receptor mimic to limit influenza A virus infection of airway epithelial cells. PMID: 23544079
- Individuals who develop non-affective psychoses have lower levels of certain acute phase proteins, including SAP, at the time of birth. PMID: 23423137
- [review] Structurally, serum amyloid P component is a prototype of the short pentraxin family. PMID: 23527487
- SAP plays a novel role in reducing the toxicity of early amyloidogenic aggregates in transthyretin amyloidosis. PMID: 23390551
- Observations suggest that serum amyloid P, at least partially, utilizes FcgammaRI and FcRgamma to inhibit fibrocyte differentiation. PMID: 22493081
- Low levels of serum amyloid P are found in the brains of individuals who remain dementia-free despite the presence of beta amyloid plaques and tangles characteristic of Alzheimer's disease pathology. PMID: 22205573
- Studies indicate that pharmaceutical grade serum amyloid P component and C-reactive protein have been isolated and purified. PMID: 22867744
- The START domain in GPBP is important for its interaction with SAP. SAP and GPBP form complexes in blood and partly colocalize in amyloid plaques from Alzheimer disease patients. PMID: 22396542
- Serum amyloid P level increased by approximately 5-fold in Parkinson's disease samples, suggesting the potential feasibility of plasma amyloid P as a marker for Parkinson's disease. PMID: 21223953
- Under physiological conditions, phosphoethanolamine binds with higher affinity to human SAP than to human CRP. PMID: 21360619
- TGF-beta driven lung fibrosis is macrophage dependent and is blocked by Serum amyloid P. PMID: 21044893
- Research suggests that local production of serum amyloid P and c-reactive protein in the Alzheimer disease brain does not substantially contribute to the CSF levels. PMID: 20930309
- Human SAP inhibits DNA-mediated innate immune activation in vitro and may limit innate and adaptive immune responses after DNA vaccination of transgenic mice. PMID: 21278351
- Serum SAP levels may serve as an easily detectable predictor for the healing of burn wounds. PMID: 20932823
- Interaction between MBL and PTX3 leads to communication between the lectin and classical complement pathways via recruitment of C1q, whereas SAP-enhanced complement activation occurs via a hitherto unknown mechanism. PMID: 21106539
- SAP has an effect on macrophages in fibrotic lung disease. PMID: 20300636
- Functional analysis has demonstrated that SAP associated with HDL promotes SR-BI-dependent cholesterol efflux and lipid-free SAP enhances ABCA1-dependent cholesterol efflux. PMID: 20189569
- The potential role of SAP in host resistance or viral virulence during influenza infection in vivo was investigated. Influenza virus infection is not affected by serum amyloid P component. Human SAP binds much more avidly than mouse SAP to the virus. PMID: 11984001
- Targeted pharmacological depletion of serum amyloid P component for treatment of human amyloidosis. PMID: 12015594
- Serum amyloid P component does not circulate in complex with C4-binding protein, fibronectin, or any other major protein ligand. PMID: 12100475
- Structures of crystalline complexes of human serum amyloid P component with its carbohydrate ligand, the cyclic pyruvate acetal of galactose, have been determined. PMID: 12126626
- Serum amyloid P component binds to late apoptotic cells and is involved in the phagocytosis of these cells by human monocyte-derived macrophages. PMID: 12528126
- Serum amyloid P component binding to Shiga toxin 2 requires both a subunit and B pentamer. PMID: 14500533
- Purified SAP inhibits fibrocyte differentiation at levels similar to those found in plasma, while depleting SAP reduces the ability of plasma to inhibit fibrocyte differentiation. PMID: 14607961
- This protein, a non-fibrillar component, causes soluble fibrils to condense into localized fibrillar aggregates with a greatly enhanced local density of fibril entanglements. PMID: 15031287
- Genetic variation in APCS is associated with amyloid polyneuropathy. PMID: 15649951
- Amyloid-associated SAP significantly increases fibrillar prion protein-related peptide-induced release of interleukin-6 and TNF-alpha from human microglia. PMID: 15837583
- This review discusses the clinical significance of different SAP levels, its role in the induction or protection from autoimmunity, and the presence of specific SAP autoantibodies in various autoimmune diseases. PMID: 16380821
- The shared specificity and shared capability to activate complement suggest that IgM and the pentraxins CRP and SAP exert similar functions in the removal of apoptotic cells. PMID: 16643876
- Monocytes bound biotinylated serum amyloid P component with avidity in a dose-dependent and saturable manner. It is speculated that binding of SAP by monocytes could be physiologically relevant at extravascular sites by influencing complement regulation. PMID: 16784490
- Serum amyloid P (SAP) and C-reactive protein (CRP) may represent different facets of inflammation. The association of SAP with cardiovascular disease in older adults further supports the role of innate immunity in atherosclerosis. PMID: 17138933
- No reduced circulating concentrations of serum amyloid P component (SAP) in patients with systemic sclerosis were observed, nor was there any evidence of an association between SAP levels and the extent or severity of fibrosis. PMID: 17530641
- SAP may modulate the inflammatory response to amyloid fibrils in atherosclerosis. PMID: 17630380
- SAP was quantitated using PVDF affinity probes and MALDI-MS. PMID: 17676666
- The complex structure between human SAP and FcgammaRIIa reveals a diagonally bound receptor on each SAP pentamer with both D1 and D2 domains of the receptor contacting the ridge helices from two SAP subunits. PMID: 19011614
- Our data suggest that measurement of cerebrospinal fluid SAP levels can aid in the identification of incipient Alzheimer's disease among mild cognitive impairment patients. PMID: 19052452
- Serum amyloid P binds to cells in the early stage of apoptosis, presumably via phosphatidylethanolamine exposed in flip-flopped membranes, suggesting a role for serum amyloid P in the clearance of these cells in vivo. PMID: 11441067
Customer Reviews
Applications : WB
Sample type: cells
Review: The relative abundance of proteins (APCS, PTGR1, FOLH1, EPRS, EEF2K, S100A16) between the control and ZEN groups analyzed by Western blot.
Q&A
What is APCS and what are its main biological functions?
APCS (Serum amyloid P component) is a 25-27 kDa glycoprotein belonging to the pentraxin family with a characteristic pentameric organization. It is predominantly synthesized by hepatocytes and circulates as a constitutive serum protein .
APCS serves multiple biological functions:
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Acts as a calcium-dependent ligand binding protein that interacts with DNA and histones
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Scavenges nuclear material released from damaged circulating cells
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Binds to apoptotic cells at early stages, potentially mediating their clearance
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May function as a chaperone by binding to proteins in pathological amyloid cross-beta fold structures
While the calculated molecular weight of APCS is 25 kDa (based on its 223 amino acid sequence), the observed molecular weight in Western blotting typically ranges from 27-29 kDa . This difference is attributed to post-translational modifications, particularly glycosylation, which increase the apparent molecular weight of the protein on SDS-PAGE gels .
What are the optimal storage conditions for APCS antibodies?
For maximum stability and retention of activity, APCS antibodies should be:
What sample types and tissues are best for validating APCS antibody specificity?
According to validation data from multiple sources:
What antigen retrieval methods are recommended for APCS immunohistochemistry?
For optimal immunohistochemical staining:
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Primary recommendation: TE buffer pH 9.0
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Alternative method: Citrate buffer pH 6.0
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For formalin-fixed tissues: Heating tissue sections in 10mM Tris with 1mM EDTA, pH 9.0, for 45 min at 95°C followed by cooling at room temperature for 20 minutes
How do monoclonal and polyclonal APCS antibodies differ in research applications?
What are the challenges in detecting APCS across different species?
Cross-species reactivity varies significantly among APCS antibodies:
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Human-specific antibodies: Many commercially available antibodies recognize only human APCS
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Human/Mouse cross-reactive: Selected antibodies show reactivity to both human and mouse APCS, enabling translational research between model systems and human samples
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Human/Mouse/Rat cross-reactive: Fewer antibodies offer triple-species reactivity, but these are valuable for comparative studies
Researchers should carefully validate cross-reactivity claims with appropriate positive and negative controls when studying APCS in animal models .
How can APCS antibodies be used to investigate the role of APCS in amyloid pathology?
APCS is implicated in amyloid pathology through its binding to proteins in the pathological amyloid cross-beta fold. Research strategies include:
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Co-localization studies: Using dual-labeling with APCS antibodies and amyloid-specific stains to demonstrate association in tissue sections
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Binding kinetics analysis: Examining APCS-amyloid interactions using purified proteins and antibodies as detection reagents
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Intervention studies: Using APCS antibodies to block APCS-amyloid interactions in experimental models
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Clearance mechanisms: Investigating how APCS affects phagocytosis of amyloid fibrils by macrophages
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Structural studies: Examining how APCS influences amyloid fibril formation and stability
What are the key considerations when using APCS antibodies in immunofluorescence studies?
For successful immunofluorescence with APCS antibodies:
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Fixation method: Paraformaldehyde fixation (4%) is generally preferred over methanol/acetone
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Dilution range: Typically 1:200-1:800 for optimal signal-to-noise ratio
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Blocking: Use 5-10% normal serum from the same species as the secondary antibody
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Controls: Include both positive controls (human liver) and negative controls (secondary antibody only)
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Counterstaining: Nuclear counterstains like DAPI help localize APCS signals relative to cellular structures
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Confocal analysis: Beneficial for precise localization, especially when examining APCS in relation to chromatin or nuclear material
How can researchers address non-specific binding when using APCS antibodies?
When experiencing high background or non-specific signals:
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Optimize antibody concentration: Titrate antibody to find the optimal working dilution
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Improve blocking: Increase blocking time or try alternative blocking reagents (BSA vs. normal serum)
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Wash thoroughly: Add additional washing steps with PBS-T (0.1% Tween-20)
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Secondary antibody controls: Include controls without primary antibody to check for secondary antibody issues
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Cross-adsorbed secondaries: Use highly cross-adsorbed secondary antibodies to reduce species cross-reactivity
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Reduce incubation time: Shorter incubation with primary antibody may reduce non-specific binding
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Pre-adsorption: In extreme cases, pre-adsorb antibody with liver powder to remove non-specific reactivity
What should researchers consider when selecting an APCS antibody for specific experimental goals?
Selection criteria should include:
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Target epitope: N-terminal (AA 1-139) versus C-terminal (AA 140-223) targeting can affect detection of potential fragments
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Validated applications: Confirm the antibody has been validated for your specific application
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Reactivity: Ensure compatibility with your experimental species
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Clone performance: Review published literature for successful use of specific clones
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Conjugation requirements: For flow cytometry or multiplexing, consider pre-conjugated antibodies
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Immunogen information: Understanding the immunogen helps predict potential cross-reactivity
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Lot-specific validation: Request lot-specific validation data from suppliers
How can researchers quantitatively assess APCS expression levels in different experimental conditions?
For quantitative analysis of APCS:
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Western blot densitometry: Normalize APCS signals to loading controls (β-actin, GAPDH)
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ELISA: Use sandwich ELISA with validated antibody pairs for quantification in solution
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Flow cytometry: Mean fluorescence intensity (MFI) provides relative quantification
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Image analysis in IHC/IF: Use software like ImageJ for quantifying staining intensity and distribution
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qPCR correlation: Correlate protein levels with mRNA expression
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Standard curves: Create standard curves using recombinant APCS protein
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Multi-method validation: Confirm findings across different quantitative methods
How are APCS antibodies being used to understand the role of APCS in apoptosis?
APCS binds to apoptotic cells at early stages, suggesting it plays a role in their recognition and clearance. Research approaches include:
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Co-staining studies: Using APCS antibodies alongside apoptosis markers (Annexin V, cleaved caspase-3)
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Functional blocking: Using APCS antibodies to inhibit APCS binding to apoptotic cells
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Time-course analysis: Examining the kinetics of APCS binding during apoptosis progression
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Mechanism studies: Investigating molecular determinants exposed on apoptotic cells that are recognized by APCS
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In vivo tracking: Using labeled APCS antibodies to track apoptotic cell clearance in animal models
What are emerging applications for APCS antibodies in disease research?
APCS antibodies are finding increasing utility in:
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Amyloidosis research: Examining APCS deposition in various forms of amyloidosis
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Neurodegenerative diseases: Studying APCS in Alzheimer's and other neurodegenerative conditions
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Inflammatory conditions: Investigating APCS as an acute phase reactant in inflammatory diseases
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Autoimmune disorders: Exploring APCS roles in clearing nuclear material and preventing autoimmunity
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Cancer biology: Understanding how APCS affects tumor cell apoptosis and immune recognition
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Biomarker development: Evaluating APCS as a potential diagnostic or prognostic biomarker
