| LPETG Motif Peptide (Fluorescent Dye-Labeled LPETGG)
Discover our advanced LPETG motif peptide, a versatile and highly specific research tool featuring the pentapeptide sequence LPETGG, available with an array of fluorescent dye labels including Cy3, Cy5, Cy5.5, Cy7, 800CW, 700DX, Janelia Fluor® 549, and Alexa546. This peptide is a critical substrate for sortase A (SrtA), a membrane-bound transpeptidase from Staphylococcus aureus that recognizes and cleaves the LPXTG motif between the threonine (T) and glycine (G) residues, covalently anchoring proteins to the bacterial cell wall. Widely utilized in cutting-edge studies, such as those employing the LIPSTIC (Labelling Immune Partnerships by SorTagging Intercellular Contacts) technique, our LPETG peptide empowers researchers to explore dynamic cell-cell interactions, protein labeling, and biomaterial engineering with exceptional precision.
Applications in Research
The LPETG motif peptide, conjugated with fluorescent dyes, is a powerhouse for diverse research applications:
- Dynamic Cell-Cell Interaction Studies: The LIPSTIC method leverages LPETG-based substrates (e.g., Biotin-aminohexanoic acid-LPETGS and SELPETGG) to label receptor-ligand interactions between immune cells, such as T cells and dendritic cells, enabling real-time tracking of immune partnerships in vivo and in vitro.
- Protein Labeling and Conjugation: SrtA-mediated transpeptidation with LPETGG allows site-specific attachment of fluorescent dyes to proteins, facilitating visualization in fluorescence microscopy, flow cytometry, and single-molecule imaging.
- Biomaterial Surface Modification: Incorporate LPETGG into synthetic scaffolds or nanoparticles to functionalize surfaces with bioactive molecules, enhancing applications in tissue engineering and drug delivery.
- Pathogen-Host Interaction Research: Study S. aureus virulence by mimicking its surface protein anchoring mechanism, providing insights into bacterial colonization and immune evasion strategies.
- Immunotherapy Development: Track immune cell dynamics and receptor engagement, supporting the design of novel immunotherapies targeting cancer or infectious diseases.
Functions and Mechanisms
The LPETGG peptide is a substrate for SrtA, which cleaves the peptide bond between T and G, forming a thioester intermediate that subsequently ligates to an oligoglycine nucleophile or cell wall components:
- SrtA Recognition: The LPETG motif is highly specific to SrtA, ensuring precise enzymatic processing and covalent attachment.
- Fluorescent Detection: Conjugation with dyes like Cy5 or 800CW enables sensitive, wavelength-specific detection across visible and near-infrared (NIR) spectra, ideal for deep-tissue imaging and multiplexing.
- Flexibility: The peptide’s compatibility with various receptor-ligand pairs and detectable labels makes it adaptable to diverse experimental designs.
Fluorescent Dye Options and Their Applications
Our LPETGG peptide is available with a range of advanced fluorescent dyes, each offering unique properties:
- Cy3: Emits at ~570 nm (greenish-yellow), widely used for its brightness and compatibility with standard TRITC filters. Researchers have employed Cy3-LPETGG in LIPSTIC studies to monitor immune cell interactions via flow cytometry.
- Cy5: Far-red emission (~670 nm), prized for its high extinction coefficient and low background in biological samples. Cy5-LPETGG has been used to label intercellular contacts in vivo, as seen in studies of T-cell priming.
- Cy5.5: NIR emission (~694 nm), offering deeper tissue penetration. Applied in LPETGG-based imaging of immune dynamics in complex tissues.
- Cy7: NIR emission (~776 nm), invisible to the naked eye, perfect for in vivo imaging. Cy7-LPETGG has been explored for tracking cell interactions in preclinical models.
- 800CW: Far-NIR emission (~794 nm), exceptional for deep-tissue imaging with minimal autofluorescence. Researchers use 800CW-LPETGG for high-sensitivity detection in live-animal studies.
- 700DX: NIR emission (~690 nm), known for photostability, used in LPETGG conjugates for prolonged imaging experiments.
- Janelia Fluor® 549: Bright, photostable yellow emission (~571 nm), a superior alternative to traditional dyes like Cy3. Its use with LPETGG enhances single-molecule imaging resolution.
- Alexa546: Orange emission (~573 nm), highly photostable and water-soluble, employed in LPETGG constructs for multicolor fluorescence microscopy.
Biological Importance
The LPETG motif is central to S. aureus virulence, as it anchors over 20 surface proteins (e.g., protein A, clumping factors) to the peptidoglycan, facilitating colonization and immune evasion. Its biological significance extends to:
- Immune Cell Dynamics: Studies using LIPSTIC (e.g., Nature, 2018) demonstrate LPETGG’s role in labeling CD40-CD40L interactions, revealing T-cell priming kinetics in lymph nodes.
- Pathogenesis Insights: LPETG mimics natural SrtA substrates, enabling researchers to dissect bacterial adhesion and host-pathogen interplay.
- Therapeutic Innovation: Fluorescent LPETGG conjugates support the development of targeted diagnostics and therapies by illuminating molecular interactions in real time.
Research Evidence
- LIPSTIC Studies: Research in PMC (e.g., PMC5777177) utilized Biotin-LPETG and fluorescent variants (e.g., Alexa647-LPETGG) to label immune cell contacts, confirming specificity via flow cytometry and microscopy.
- S. aureus Research: Publications like PLOS ONE (2014) report FITC-LPETG incorporation into bacterial cell walls, peaking in stationary phase, underscoring its SrtA dependency.
- Protein Labeling: Cy5-LPETGG and Janelia Fluor® 549-LPETGG have been adopted for site-specific protein tagging, enhancing visualization in live-cell imaging (eLife, 2016).
Why Choose Our LPETG Motif Peptide?
- Diverse Dye Options: From Cy3 to 800CW, tailor your experiment with the perfect spectral range.
- High Purity: Synthesized at >98% purity, validated by HPLC and mass spectrometry.
- Customizable: Offered in lyophilized or solubilized forms, with scalable quantities.
Harness the power of our fluorescent dye-labeled LPETGG peptide to illuminate your research in immunology, microbiology, and beyond. Order now and redefine precision in your scientific discoveries!
Reference:
1. Proximity-dependent labeling identifies dendritic cells that drive the tumor-specific CD4+ T cell response, Science Immunology, 4 Oct 2024, Vol 9, Issue 100, DOI: 10.1126/sciimmunol.adq8843
2. Nakandakari-Higa S, Walker S, Canesso MCC, et al. Universal recording of immune cell interactions in vivo. Nature. 2024 Mar;627(8003):399-406. doi: 10.1038/s41586-024-07134-4.
3. Lee, C.S., Chen, S., Berry, C.T. et al. Fate induction in CD8 CAR T cells through asymmetric cell division. Nature (2024). https://doi.org/10.1038/s41586-024-07862-7
4. Pasqual, G., Chudnovskiy, A., Tas, J. et al. Monitoring T cell–dendritic cell interactions in vivo by intercellular enzymatic labelling. Nature 553, 496–500 (2018). https://doi.org/10.1038/nature25442
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