YPR195C Antibody

What is YPR195C and what is its functional significance in yeast?

YPR195C is classified as a putative uncharacterized protein in Saccharomyces cerevisiae with a sequence length of 109 amino acids. The full sequence is MNSLIPLLVEASTYIVRGESSISIAIGIGPQASRSVPYHILCRGCDGTVTTFRTWHTQPLGPCNTIIIGRKGNETTGGAEQRRQQHLTSDSATKASLVGFCGLYYYFRK . While its precise biological function remains to be fully characterized, the protein contains structural motifs suggesting potential involvement in cellular stress responses. The presence of cysteine-rich regions (particularly PYHILCRGCDGT) indicates it may function in metal binding or redox-related processes, potentially connecting to arsenite/arsenate resistance mechanisms observed in some yeast strains .

What types of YPR195C antibodies are available for research applications?

Several monoclonal antibody combinations targeting different regions of the YPR195C protein are commercially available, including:

• N-terminal antibodies (X-Q06594-N): A combination of mouse monoclonal antibodies targeting three synthetic peptides from the N-terminus region .

• C-terminal antibodies (X-Q06594-C): Mouse monoclonal antibodies raised against three synthetic peptides representing the C-terminus sequence .

• Mid-region antibodies (X-Q06594-M): Monoclonal antibodies targeting non-terminus (middle) sequences of the protein .

Each antibody combination has been validated by ELISA with titers of approximately 10,000, corresponding to detection sensitivity of approximately 1 ng of target protein in Western blot applications .

What experimental validation steps should be performed before using YPR195C antibodies?

Prior to implementation in critical experiments, YPR195C antibodies should undergo systematic validation:

• Specificity testing:

  • Western blot analysis using wild-type yeast lysates (positive control)

  • Parallel testing with YPR195C deletion strain lysates (negative control)

  • Peptide competition assays to confirm epitope specificity

• Cross-reactivity assessment:

  • Testing against closely related yeast species

  • Evaluation using recombinant expression systems

• Application-specific validation:

  • For Western blotting: Confirmation of expected molecular weight (~12 kDa)

  • For immunoprecipitation: Analysis of pull-down efficiency and specificity

  • For immunofluorescence: Optimization of fixation and permeabilization conditions

Thorough validation ensures reliable experimental outcomes and prevents misinterpretation of results, particularly important when working with antibodies targeting uncharacterized proteins like YPR195C.

What are the optimal conditions for using YPR195C antibodies in Western blotting?

Based on the technical specifications and general principles for working with yeast proteins of this size, the following protocol is recommended:

Sample preparation:

• Extract proteins using glass bead lysis in buffer containing protease inhibitors

• Quantify protein concentration (aim for 20-50 μg total protein per lane)

• Denature samples at 95°C for 5 minutes in reducing sample buffer

Gel electrophoresis and transfer:

• Use 15-18% polyacrylamide gels for optimal resolution of small proteins

• Transfer to PVDF membrane (recommended over nitrocellulose for small proteins)

• Consider using specialized transfer conditions (low methanol, longer transfer times) for this small protein

Antibody incubation:

• Block with 3-5% BSA in TBST (1 hour at room temperature)

• Primary antibody dilution: 1:1000 to 1:5000 based on ELISA titer of 10,000

• Incubate overnight at 4°C with gentle agitation

• Wash 4-5 times with TBST (5 minutes each)

• Secondary antibody: HRP-conjugated anti-mouse IgG at 1:5000-1:10000

• Incubate 1 hour at room temperature

• Wash 4-5 times with TBST

Detection:

• Use enhanced chemiluminescence (ECL) substrate

• Expected sensitivity: ~1 ng of target protein

• For quantitative analysis, consider fluorescent secondary antibodies and imaging

How can YPR195C antibodies be effectively used in immunoprecipitation studies?

For immunoprecipitation of YPR195C from yeast lysates:

Lysate preparation:

• Use gentle lysis conditions (e.g., spheroplasting followed by detergent lysis)

• Include protease and phosphatase inhibitors

• Clear lysate by centrifugation (14,000 × g, 15 minutes, 4°C)

Immunoprecipitation procedure:

• Pre-clear lysate with protein G beads (1 hour, 4°C)

• Add 2-5 μg of YPR195C antibody per 500 μg of total protein

• Incubate overnight at 4°C with gentle rotation

• Add protein G beads and incubate 2-4 hours at 4°C

• Wash beads extensively (at least 5 washes with lysis buffer)

• Elute proteins by boiling in sample buffer

Controls and validation:

• Include IgG control precipitation

• Confirm precipitation efficiency by Western blotting a small portion of the IP

• For interaction studies, consider using cross-linking before lysis

• For mass spectrometry analysis, elute with peptide competition or acid elution

The combination of multiple monoclonal antibodies in each preparation may provide improved immunoprecipitation efficiency compared to single monoclonal antibodies.

What strategies can enhance YPR195C detection sensitivity in challenging samples?

Several approaches can improve detection sensitivity when working with low-abundance YPR195C:

Sample enrichment techniques:

• Subcellular fractionation to reduce sample complexity

• TCA precipitation to concentrate proteins

• Immunoaffinity purification prior to analysis

Signal amplification methods:

• Tyramide signal amplification (TSA) can increase sensitivity 10-100 fold

• Poly-HRP secondary antibodies containing multiple HRP molecules

• Biotin-streptavidin amplification systems

Antibody optimization:

• Using a cocktail approach with multiple epitope-targeting antibodies

• Optimizing incubation conditions (longer incubation at 4°C)

• Pre-adsorption to reduce background

Detection system enhancements:

• Super-sensitive ECL substrates

• Digital imaging with longer exposure times

• Fluorescent secondary antibodies with laser-based scanning

Example sensitivity comparison:

Implementation of these techniques should be validated with appropriate controls to ensure that the enhanced signal represents specific detection of YPR195C.

How can YPR195C antibodies be utilized to investigate protein localization and trafficking?

YPR195C antibodies enable detailed localization studies through multiple complementary approaches:

Immunofluorescence microscopy:

• Fix yeast cells with 3.7% formaldehyde (30 minutes)

• Prepare spheroplasts with zymolyase treatment

• Permeabilize with 0.1% Triton X-100

• Block with 1% BSA in PBS

• Incubate with YPR195C antibody (1:100-1:500 dilution)

• Detect with fluorophore-conjugated secondary antibody

• Counterstain with DAPI and appropriate organelle markers

Subcellular fractionation with immunoblotting:

• Separate cellular components into distinct fractions (cytosol, nucleus, membrane, etc.)

• Analyze each fraction by Western blotting with YPR195C antibodies

• Include marker proteins for each subcellular compartment as controls

• Quantify relative distribution across fractions

Immunoelectron microscopy for high-resolution localization:

• Fix cells with glutaraldehyde and embed in resin

• Prepare ultrathin sections

• Immunolabel with YPR195C antibody and gold-conjugated secondary antibody

• Visualize with transmission electron microscopy for precise subcellular localization

Trafficking studies:

• Monitor localization changes in response to environmental stressors

• Track dynamics using time-course experiments

• Combine with GFP-tagged complementary proteins for co-localization studies

These approaches can help establish YPR195C's cellular context and potentially provide functional insights for this uncharacterized protein.

What role might YPR195C play in arsenic resistance mechanisms in yeast?

While direct evidence linking YPR195C to arsenic resistance is not established in the provided search results, the presence of cysteine-rich regions in YPR195C suggests potential involvement in metal detoxification pathways. To investigate this hypothesis using YPR195C antibodies:

Expression analysis in resistant strains:

• Compare YPR195C protein levels between arsenic-sensitive and arsenic-resistant yeast strains using Western blotting

• Examine if YPR195C shows altered expression after arsenite/arsenate exposure

• Correlate expression levels with resistance phenotypes

Co-localization with known arsenic resistance proteins:

• Use YPR195C antibodies alongside antibodies against known arsenite/arsenate resistance proteins (ARR1, ARR2, ARR3)

• Examine potential co-localization or redistribution after arsenic treatment

• Determine if YPR195C localizes to regions of subtelomeric gene cluster expansion associated with arsenic resistance

Protein-protein interaction studies:

• Perform co-immunoprecipitation with YPR195C antibodies from arsenic-treated cells

• Identify potential interactions with arsenic detoxification pathway components

• Validate interactions through reciprocal co-IP and proximity ligation assays

Functional studies with protein depletion:

• Create conditional YPR195C depletion strains

• Assess arsenic sensitivity compared to wild-type cells

• Examine if overexpression affects resistance

This systematic approach could establish whether YPR195C functions within the network of proteins associated with the subtelomeric expansion of yeast genes involved in arsenic resistance .

How can researchers perform detailed epitope mapping of YPR195C antibodies?

Precise epitope mapping provides critical information about antibody specificity and can inform experimental design. Several methodologies can be employed:

Peptide array analysis:

• Synthesize overlapping peptides (10-15 amino acids) spanning the entire 109-amino acid YPR195C sequence

• Immobilize peptides on membrane or glass surface

• Probe with YPR195C antibodies

• Detect binding with appropriate secondary antibody

• Identify specific peptide sequences recognized by each antibody

Alanine scanning mutagenesis:

• Generate a series of YPR195C mutants with systematic alanine substitutions

• Express mutant proteins in a heterologous system

• Test antibody binding by Western blot or ELISA

• Mutations that eliminate binding identify critical epitope residues

Hydrogen-deuterium exchange mass spectrometry (HDX-MS):

• Compare deuterium uptake rates between free YPR195C and antibody-bound YPR195C

• Regions with reduced exchange when antibody-bound represent the epitope

• This provides structural information about the antibody-antigen interface

X-ray crystallography:

• For highest resolution epitope mapping

• Crystallize the antibody-antigen complex

• Determine atomic structure of the interaction interface

It's worth noting that epitope determination services are available from the antibody provider at $100 per combination , which may be more efficient than in-house mapping for many laboratories.

What experimental approaches can resolve conflicting results from different YPR195C antibodies?

When different YPR195C antibodies yield inconsistent results, a systematic investigation is necessary:

Technical validation:

• Repeat experiments under identical conditions with all antibodies

• Include appropriate positive and negative controls

• Test different sample preparation methods (native vs. denaturing conditions)

• Validate each antibody independently against recombinant YPR195C

Epitope accessibility analysis:

• Determine if discrepancies relate to conformational differences

• Test if detergents or chaotropic agents affect antibody recognition

• Evaluate whether protein-protein interactions might mask certain epitopes

• Examine if post-translational modifications affect antibody binding

Cross-reactivity assessment:

• Test antibodies on YPR195C knockout strains to confirm specificity

• Perform peptide competition assays

• Consider cross-reactivity with related proteins

Resolution strategies:

• Use antibody combinations targeting different epitopes simultaneously

• Implement orthogonal detection methods (mass spectrometry, tagged protein)

• Consider the biological context when interpreting differences

Conflicting results should be viewed as potentially informative rather than problematic, as they may reveal important aspects of YPR195C biology such as processing, modifications, or interactions.

Why might YPR195C antibodies show weak or variable signal intensity in Western blots?

Several factors can contribute to weak or inconsistent YPR195C detection:

Protein extraction issues:

• Inefficient cell lysis (especially problematic with yeast cell walls)

• Protein degradation during sample preparation

• Poor solubilization of membrane-associated proteins

• Precipitation during storage or handling

Technical considerations:

• Insufficient protein loading (especially important for low-abundance proteins)

• Inefficient transfer of small proteins to membrane

• Over-blocking membrane or excessive washing

• Suboptimal antibody concentration

• Degraded or improperly stored antibody

Biological variables:

• Growth phase-dependent expression

• Strain-specific expression levels

• Environmental conditions affecting YPR195C expression

• Post-translational modifications altering epitope recognition

Recommended solutions:

• Optimize extraction protocol (consider bead-beating or enzymatic cell wall digestion)

• Include protease inhibitors and maintain samples at 4°C

• Use 15-18% gels with specialized transfer conditions for small proteins

• Optimize antibody concentration through dilution series testing

• Consider signal enhancement methods if protein is low abundance

These systematic troubleshooting approaches should be documented to establish reproducible conditions for YPR195C detection.

How can background and non-specific binding be minimized when using YPR195C antibodies?

High background or non-specific signals can obscure legitimate YPR195C detection:

Blocking optimization:

• Test different blocking agents (BSA, milk, commercial blockers)

• Increase blocking time or concentration

• Add 0.1-0.3% Tween-20 to reduce hydrophobic interactions

Antibody dilution and incubation:

• Optimize primary antibody concentration (typically 1:1000-1:5000)

• Extend incubation time with more dilute antibody

• Perform incubations at 4°C to increase binding specificity

Wash optimization:

• Increase number and duration of wash steps

• Use higher ionic strength buffer (up to 500 mM NaCl)

• Try different detergents (Tween-20, Triton X-100, NP-40)

Antibody pre-absorption:

• Pre-incubate antibody with yeast lysate from YPR195C knockout strain

• Use acetone powder from non-expressing cells for pre-absorption

• Consider commercial antibody pre-absorption solutions

Sample preparation:

• Ensure complete protein denaturation for Western blotting

• Include reducing agents (DTT or β-mercaptoethanol)

• Filter lysates before use to remove particulates

The monoclonal nature of the available YPR195C antibody combinations should provide better specificity compared to polyclonal antibodies, but optimization remains important for optimal results.

How can YPR195C antibodies be used to study protein-protein interactions?

YPR195C antibodies enable several approaches for investigating protein interaction networks:

Co-immunoprecipitation (Co-IP):

• Lyse cells under non-denaturing conditions

• Immunoprecipitate YPR195C using specific antibodies

• Analyze co-precipitated proteins by Western blotting or mass spectrometry

• Validate interactions with reciprocal Co-IP

• Consider using chemical crosslinking to capture transient interactions

Proximity Ligation Assay (PLA):

• Use YPR195C antibody with antibody against suspected interaction partner

• Secondary antibodies with oligonucleotide probes generate fluorescent signal when proteins are in close proximity

• Enables visualization of interactions in situ with subcellular localization information

Pull-down assays:

• Immobilize YPR195C antibodies on solid support

• Incubate with cell lysate

• Wash and elute bound proteins

• Identify interacting partners by mass spectrometry

Quantitative considerations:

• Include appropriate negative controls (IgG, unrelated protein)

• Validate key interactions with multiple methods

• Consider strength and stoichiometry of interactions

• Assess whether interactions are constitutive or condition-dependent

These approaches can help establish the functional context of the uncharacterized YPR195C protein through its interaction network.

How should researchers quantify YPR195C expression levels across different experimental conditions?

Accurate quantification of YPR195C expression requires rigorous methodological approaches:

Western blot quantification:

• Include dilution series of recombinant YPR195C standard (if available)

• Load equal amounts of total protein across samples

• Include multiple loading controls (housekeeping proteins)

• Use fluorescent secondary antibodies for wider linear detection range

• Analyze band intensity with appropriate software (ImageJ, etc.)

• Normalize to loading controls

ELISA-based quantification:

• Develop sandwich ELISA using different YPR195C antibodies

• Generate standard curve with recombinant protein

• Ensure samples fall within the linear range of the assay

• Include technical replicates for each sample

Mass spectrometry quantification:

• Use targeted MS approaches (MRM/PRM) for highest specificity

• Include isotope-labeled peptide standards

• Monitor multiple peptides from YPR195C

• Normalize to stable reference proteins

Statistical analysis:

• Perform at least three biological replicates

• Apply appropriate statistical tests

• Consider fold-change and statistical significance

• Report variability measures (standard deviation, standard error)

A standardized quantification approach ensures reliable comparison of YPR195C expression across different experimental conditions and between laboratory groups.