XPNPEP3 Antibody

Definition and Classification of XPNPEP3 Antibodies

XPNPEP3 antibodies are immunoglobulins specifically raised against X-Prolyl Aminopeptidase 3 (XPNPEP3), also known as Aminopeptidase P3 or APP3. These antibodies can be classified according to several characteristics:

Classification by Host Species and Clonality

Based on the available research materials, XPNPEP3 antibodies are primarily produced in two host species with different clonality profiles:

Monoclonal antibodies offer high specificity for single epitopes, while polyclonal antibodies recognize multiple epitopes, providing stronger detection signals but potentially lower specificity .

Classification by Conjugation Status

Most commercially available XPNPEP3 antibodies are unconjugated primary antibodies, requiring secondary detection systems for visualization in various applications .

Target Protein: XPNPEP3 Biological Significance

Understanding the target protein's function provides context for antibody applications in research:

XPNPEP3 Protein Function

XPNPEP3 is an enzyme that catalyzes the removal of penultimate prolyl residues from the N-termini of peptides, such as Leu-Pro-Ala. It also demonstrates low activity towards peptides with Alanine or Serine at the P1 position . The protein exists in two primary isoforms:

• Mitochondrial XPNPEP3 (XPNPEP3m): Localizes to mitochondria

• Cytosolic XPNPEP3 (XPNPEP3c): Found in the cytoplasm

Research indicates that XPNPEP3m is co-immunoprecipitated with respiratory chain complex I and is required for the stability and activity of this complex . Additionally, XPNPEP3 isoform 1 promotes TNFRSF1B-mediated phosphorylation pathways and may function as an adapter protein, independent of its peptidase activity .

Tissue Expression Profile

XPNPEP3 is widely expressed across multiple tissues, with notable presence in kidney and skeletal muscle . This expression pattern correlates with the pathologies observed in conditions associated with XPNPEP3 dysfunction.

Applications of XPNPEP3 Antibodies in Research

XPNPEP3 antibodies have been validated for multiple laboratory techniques:

These applications enable researchers to investigate XPNPEP3 expression patterns, protein levels, subcellular localization, and functional relationships in various experimental contexts .

XPNPEP3 Monoclonal Antibody (OTI2D5)

This mouse monoclonal antibody is commercially available as TrueMAB™ from OriGene:

This antibody has been validated for detecting XPNPEP3 across multiple species and applications .

XPNPEP3 Monoclonal Antibody (OTI5G2)

Another mouse monoclonal antibody available from OriGene:

This antibody has been specifically validated for human XPNPEP3 detection .

Anti-XPNPEP3 Antibody (ab224211)

This rabbit polyclonal antibody is manufactured by Abcam:

This antibody has been validated through paraffin-embedded human stomach tissue staining and Western blot applications .

XPNPEP3 in Disease Research

XPNPEP3 antibodies have proven valuable in elucidating the role of this protein in various pathological conditions:

Nephronophthisis-Like Ciliopathy (NPHPL1)

Mutations in XPNPEP3 (also known as NPHPL1) have been identified in patients with nephronophthisis-like ciliopathy. Novel compound heterozygous mutations (c.634G>A/c.761G>T and c.-87C>T/c.1261C>G) were detected in patients presenting with:

• Renal lesions

• Bone cysts

• Hyperechogenic kidneys

• Proteinuria

• Hematuria

Patient-derived lymphoblasts carrying these mutations exhibited:

• Elevated mitochondrial XPNPEP3 levels

• Reduced mRNA degradation

• Mitochondrial dysfunction

• Elongated primary cilium

XPNPEP3 antibodies enabled researchers to detect the increased expression of mitochondrial XPNPEP3 (XPNPEP3m) while observing no change in cytosolic XPNPEP3 (XPNPEP3c) through Western blotting and immunofluorescence techniques .

Acute Myocardial Infarction (AMI)

Recent research has revealed XPNPEP3's potential role in acute myocardial infarction:

• XPNPEP3 was identified as highly associated with AMI among differentially expressed genes

• XPNPEP3 demonstrated negative correlation with inflammatory response scores

• A diagnostic model based on XPNPEP3 expression showed excellent diagnostic performance with an area under the curve (AUC) of 93.38%

• Molecular docking analysis identified compound DB06909 as a potential XPNPEP3 inhibitor

These findings suggest XPNPEP3 may serve as both a diagnostic marker and therapeutic target in AMI .

Cardiomyopathy and Neuromuscular Disorders

Loss-of-function variants in XPNPEP3, typically associated with renal manifestations, have also been linked to cardiomyopathy and neuromuscular symptoms. Specific mitochondrial respiratory chain enzyme deficiencies were observed in cardiac tissue, particularly isolated deficiency in complex IV activity (cytochrome c oxidase) .

Research Techniques Employing XPNPEP3 Antibodies

Multiple experimental approaches utilize XPNPEP3 antibodies to investigate protein function and disease mechanisms:

Western Blotting Analysis

Western blotting with XPNPEP3 antibodies has been crucial in determining expression levels in patient-derived cells versus controls. For example, researchers detected approximately 50% increase in mitochondrial XPNPEP3 expression in patient lymphoblasts carrying compound heterozygous mutations .

Immunofluorescence Microscopy

Immunofluorescence studies using XPNPEP3 antibodies have been instrumental in:

• Determining subcellular localization of XPNPEP3 isoforms

• Investigating colocalization with other proteins

• Examining the relationship between XPNPEP3 and cellular structures like mitochondria and primary cilia

For instance, exogenous XPNPEP3m tagged with hemagglutinin was shown to exclusively localize in mitochondria and was absent from cilia .

Co-Immunoprecipitation Studies

XPNPEP3 antibodies have been used in co-immunoprecipitation experiments demonstrating that mitochondrial XPNPEP3 interacts with respiratory chain complex I components, supporting its role in maintaining the stability and activity of this complex .

Technical Considerations for XPNPEP3 Antibody Usage

When working with XPNPEP3 antibodies, researchers should consider several important factors:

Isoform Specificity

Since XPNPEP3 exists in both mitochondrial and cytosolic isoforms, antibody selection should consider which isoform is relevant to the research question. Some antibodies may preferentially detect one isoform over the other .

Recommended Dilutions

Optimal antibody concentrations vary by application and specific antibody:

• Western blotting: 1/250 to 1/1000

• Immunohistochemistry: 1/200

• Immunofluorescence: typically 1/100 to 1/500

• Flow cytometry: follow manufacturer's recommendations

Testing a range of dilutions for each new experimental system is advisable .