Product Description | 
The peptide sequence Cys-LPETGS is a synthetic construct that combines a cysteine residue at the N-terminus with the LPETG motif, a well-characterized recognition sequence for the enzyme sortase A (SrtA). The LPETG motif is crucial for SrtA-mediated transpeptidation reactions, where SrtA cleaves between the threonine and glycine residues, facilitating the covalent attachment of proteins to the cell wall in Gram-positive bacteria. The addition of an N-terminal cysteine introduces a reactive thiol group, enabling site-specific conjugation through maleimide chemistry, which forms stable thioether bonds with thiol-containing molecules. Applications: The dual functionality of Cys-LPETGS makes it a versatile tool in biochemical and biomedical research. The N-terminal cysteine enables conjugation with maleimide-activated fluorescent dyes, such as Alexa Fluor 488, Cy5, and Cy7, facilitating applications in imaging and flow cytometry. Additionally, the peptide can be conjugated to lipids like DSPE-PEG2000, enabling the incorporation of proteins or peptides into liposomal membranes for targeted drug delivery systems. The LPETG motif permits enzymatic ligation to proteins or peptides bearing N-terminal oligoglycine sequences via SrtA, allowing for the construction of complex, site-specific bioconjugates. This combination of chemical and enzymatic conjugation strategies expands the utility of Cys-LPETGS in the development of multifunctional biomolecules. Biological Importance: The LPETG motif within Cys-LPETGS is recognized by SrtA, which plays a pivotal role in anchoring surface proteins to the cell wall in Gram-positive bacteria, a process essential for bacterial virulence and adherence. By mimicking this natural substrate, Cys-LPETGS serves as a valuable tool for studying SrtA-mediated processes and for engineering proteins with defined orientations and functionalities. The inclusion of the N-terminal cysteine allows for precise chemical modifications, facilitating the development of targeted therapeutics, imaging agents, and vaccine candidates. The ability to combine enzymatic specificity with chemical versatility makes Cys-LPETGS a powerful component in the design of advanced biomolecular constructs. An illustrative example of utilizing the LPETG motif for fluorescent labeling is presented in a study published in Nature Communications. In this research, scientists employed an evolved sortase A (eSrtA) enzyme to catalyze the conjugation of Alexa Fluor 750-labeled LPETG peptides onto pentaglycine-modified polyurethane catheters implanted in mice. This enzymatic reaction facilitated real-time, in vivo fluorescent imaging of the catheter surfaces. The study demonstrated that the fluorescent signal from the LPETG-tagged probes could be effectively removed by administering eSrtA along with a triglycine peptide, showcasing the reversible nature of this labeling technique. This approach underscores the potential of LPETG-mediated conjugation for dynamic and controllable surface modifications in biomedical applications. Reference: Ham, H., Qu, Z., Haller, C. et al. In situ regeneration of bioactive coatings enabled by an evolved Staphylococcus aureus sortase A. Nat Commun 7, 11140 (2016). https://doi.org/10.1038/ncomms11140 |
Scientific Background | CLPETGS is a 7-residue synthetic peptide with the sequence Cys-Leu-Pro-Glu-Thr-Gly-Ser. The sequence contains 1 cysteine residue, providing potential thiol/disulfide chemistry when the thiol is available. These sequence-derived properties describe the reagent chemically; no specific receptor, enzyme, pathway, disease association, or biological activity is assigned without product-specific experimental evidence. |
Experimental Notes | Sequence-derived chemical properties support reagent selection and experimental planning but do not establish biological function. Solubility, aggregation, adsorption, conjugation efficiency, and assay performance should be validated under the intended experimental conditions. |
