FH11 Antibody
Description
FH11 as a Substrate-Inspired Probe for Bacterial Effector Proteins
Primary Source:
Structure and Function
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Design: FH11 is a synthetic probe containing:
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An AOMK-reactive group (irreversible inhibitor targeting cysteine proteases).
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A Gly-Asp-Ala peptide linker (mimics the cleavage site of the bacterial effector AvrPphB).
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A rhodamine reporter tag (enables fluorescent detection).
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Target: Binds specifically to AvrPphB, a cysteine protease effector produced by Pseudomonas syringae.
Key Findings
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Labeling Specificity: FH11 selectively labels active AvrPphB in bacterial and plant cell extracts, with no cross-reactivity to inactive mutants (e.g., C98S) .
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pH Sensitivity: Optimal labeling occurs at pH 7–8, aligning with AvrPphB’s activity in host cytoplasm .
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Functional Inhibition: FH11 suppresses AvrPphB-mediated cleavage of PBS1 (a plant kinase), confirming its role as a protease inhibitor .
| Property | Detail |
|---|---|
| Target | AvrPphB (cysteine protease) |
| Detection Method | Fluorescence (rhodamine tag) |
| Inhibitory Effect | Blocks PBS1 cleavage, preventing pathogen virulence |
F11 as an Anti-HA Stalk Antibody for Influenza Neutralization
Primary Source:
Background
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Antibody Type: IgG/IgA monoclonal antibody isolated from humans vaccinated with an intranasal influenza vaccine.
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Target: Hemagglutinin (HA) stalk domain of influenza A viruses (e.g., H1N1, H3N2, H5N1).
Engineering and Applications
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Mutagenesis: A single amino acid substitution in the F11 light chain (e.g., L34Q) enhanced neutralization breadth, enabling activity against F11-resistant H1N1 variants .
| Property | Detail |
|---|---|
| Target Epitope | HA stalk hydrophobic cleft |
| Neutralization Mechanism | Steric hindrance of HA conformational changes |
| Therapeutic Potential | Basis for universal influenza vaccine design |
Distinguishing FH11 (Probe) vs. F11 (Antibody)
While both compounds share similar nomenclature, their roles and targets differ fundamentally:
Research Implications
Product Specs
Constituents: 50% Glycerol, 0.01M Phosphate Buffered Saline (PBS), pH 7.4
Target Background
Q&A
Given the lack of specific information about the "FH11 Antibody" in the provided search results, I will create a general FAQ collection for researchers focusing on antibody-related research scenarios. This will cover both basic and advanced research questions relevant to antibody studies.
Answer:
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Specificity: Ensure the antibody targets the correct protein and localizes to the expected subcellular compartment. This can be verified by using negative controls (cells lacking the target protein) and positive controls (cells known to express the target).
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Optimized Protocol: Use established fixation, permeabilization, and antibody dilution conditions to enhance specificity and reduce background noise.
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Consistency: Verify that the antibody performs consistently across different batches and experimental conditions.
Answer:
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Control Experiments: Conduct control experiments to ensure that the observed differences are not due to variations in sample preparation or antibody batch.
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Quantification: Quantify staining intensity using image analysis software to provide a more objective comparison.
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Literature Review: Consult existing literature to see if similar discrepancies have been reported and how they were addressed.
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Specificity and Sensitivity: Choose antibodies with high specificity and sensitivity for the target antigen.
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Cross-reactivity: Assess potential cross-reactivity with other proteins, especially if working with closely related species or proteins.
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Optimization: Optimize antibody concentration and incubation conditions to minimize background and maximize signal.
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Early Assessment: Evaluate manufacturability early in the development process to identify potential issues such as aggregation or low expression levels.
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Sequence Optimization: Optimize the antibody sequence to improve expression and stability, which can involve humanization or framework modifications.
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Process Development: Develop scalable production processes that maintain antibody integrity and yield.
Answer:
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Single-Chain Variable Fragments (scFvs): Use scFvs for higher specificity and reduced background due to their smaller size and monovalent binding.
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Bispecific Antibodies: Employ bispecific antibodies to target two epitopes, enhancing specificity and reducing non-specific binding.
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Antibody Conjugates: Utilize antibody conjugates with fluorophores or other tags to improve detection sensitivity and specificity.
Answer:
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Family Screening: Cascade testing involves screening relatives of individuals with confirmed genetic conditions to identify carriers or affected family members.
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Genetic Markers: Use genetic markers or antibodies to detect specific proteins associated with genetic conditions, facilitating early diagnosis and intervention.
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Cost-Effectiveness: Evaluate the cost-effectiveness of different cascade testing protocols to optimize resource allocation and patient outcomes.
Example Data Table for Cascade Testing Outcomes
| Protocol | Yield of Tested Relatives | Confirmed Cases | Cost-Effectiveness |
|---|---|---|---|
| Direct | 80% | 20% | High |
| Indirect | 60% | 15% | Moderate |
| Combined | 85% | 22% | Very High |
This table illustrates how different cascade testing protocols can vary in terms of yield, confirmed cases, and cost-effectiveness, which are crucial considerations in genetic studies involving antibodies or proteins.
