Custom Labeling
* Please kindly note that our products and services can only be used to support research purposes (Not for clinical use).
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The peptide labeling belongs to a kind of peptide modification synthesis, and the addition of an appropriate label in the peptide molecule is helpful for the study of the peptide. Creative Peptides has vast experience in designing and producing labeled peptides and provides all common peptide labeling services. Our experienced technicians will ensure that the most suitable methods and techniques are selected for each peptide project.
What is peptide labeling?
Peptide labeling is a technique employed to attach a chemical or a fluorophore to a peptide sequence, thereby imparting specific properties or enabling visualization under various analytical techniques. This process facilitates the study of peptide interactions, localization within cells or tissues, and elucidation of molecular pathways. By selectively modifying peptides with labels, researchers can track their behavior, monitor changes, and gain insights into biological phenomena with unparalleled precision.
What are the advantages of peptide labeling？
Improved detection: Peptide labeling enhances detection of target peptides in complex biological mixtures such as serum or cellular extracts.
Easier separation: By labeling peptides with colored or fluorescent dyes, they can be easily separated from non-labeled components of a mixture, thus simplifying analytical processes such as chromatography.
Enhanced imaging: In biological imaging, labeled peptides can be used as specific markers for cells, tissues, and organs. This is helpful in studying biological processes and diseases.
Stability: Some labels can improve the stability of peptides in different environments, making them more suitable for various experimental conditions.
Enables tracking: Peptide labeling can allow for the tracking of peptides and proteins within a cellular context, providing insights into protein-protein interaction or the movement and localization of proteins within a cell.
Increases specificity: Peptide labeling can increase the specificity of binding to target molecules, improving the accuracy of experimental results.
Significance in biomedical research
Through the labeling of synthetic peptides, scientists can identify all the components in the biological system and monitor the quantitative changes that may occur in different metabolic stages (such as different stages of the cell cycle). Labeled peptides have been widely used.
Visualization and tracking: Labeling peptides with fluorescent dyes or radioactive isotopes allows researchers to visualize and track their movement within cells or organisms. This is especially important for studying processes such as protein-protein interactions, cellular trafficking, and signaling pathways.
Quantification: By labeling peptides, researchers can quantify the amount of peptide present in a sample using techniques such as fluorescence spectroscopy or radioactivity assays. This quantitative information is essential for understanding the dynamics of biological processes and for comparing experimental conditions.
Proteomics and biomarker discovery: Peptide labeling is commonly used in proteomics research to identify and quantify proteins in complex biological samples. By labeling peptides with tags that enable mass spectrometry analysis, researchers can identify proteins present in a sample and discover potential biomarkers for diseases or physiological conditions.
Drug discovery and development: Labeled peptides serve as invaluable tools for screening compound libraries, assessing drug efficacy, and elucidating the mechanism of action of candidate molecules. Moreover, peptide labeling facilitates the development of peptide-based therapeutics, including peptide drugs, peptide conjugates, and targeted delivery systems, offering novel approaches for the treatment of various diseases, including cancer, infectious diseases, and metabolic disorders.
Diagnostic applications: Labeled peptides can be used in diagnostic assays to detect specific biomolecules or pathological conditions. For example, labeled peptides can be employed in immunoassays or imaging techniques to detect the presence of disease markers in patient samples, aiding in early disease diagnosis and monitoring.
Targeted therapy: Peptide labeling can facilitate targeted therapy approaches by conjugating therapeutic agents to peptides that specifically bind to diseased cells or tissues. This allows for the precise delivery of therapeutic payloads, minimizing off-target effects and improving treatment outcomes.
Analysis & quality
Peptide labeling QC/QA
Our standard quality control includes LC-MS with ion trap, quadrupole or TOF detection, MALDI-MS, or HPLC.
We provide a variety of optional peptide analysis services, such as
- AAA (amino acid analysis)
- UHPLC (Ultra-high-performance liquid chromatography)
- Determination of residual solvents and water
- Solubility or stability test
Labels we provide
Besides the following detailed peptide labeling services, Creative Peptides can also provide you with a variety of reactive tags linked to peptides
- Azide (reaction with alkanes-click chemistry)
- Maleimide (reacts with sulfhydryl groups, such as cysteine)
- Mercaptan (reaction with maleimide)
- Cys (Pys/Npys) (reacts with mercaptans to form disulfides)
All custom peptide labeling services include
- Free peptide consultation and design
- Custom peptides on demand
- Specialty peptide modifications
- Mass spectrometry and HPLC chromatogram to confirm purity and identity
- Provided as a lyophilized powder to minimize oxidation
- Scale-up production
- Technical support and training
Service details
Isotopic labeling refers to the replacement of atoms with different heavy isotopes. A common alternative is 12C by 13C, of 14N by 15N, and of 1H by 2H (deuterium). Creative Peptides can provide customized peptides labeled with stable isotopes including 2H, 15N & 13C, respectively, or a combination of 15N & 13C. Even when the peptides are attached with specific modification motifs.
Studies of peptide-protein or protein-protein interactions often involve the use of cross-linking agents, of which photo cross linkers are an effective tool. Creative Peptides can connect appropriate photo cross linkers to peptide, and commonly used photo cross linkers are Bpa and DMNB.
Spin labeling is also a good label pattern in studying peptide-protein and protein-protein interactions. The combination of site-directed spin labeling (SDSL) technology and electron paramagnetic spectroscopy (EPR) is a mature method that is widely used in protein and peptide science. Creative Peptides can apply this technique to the research of interaction of peptides with biofilms, as well as the secondary structure, position, and orientation of peptides in membrane systems. TEMPYO and TOAC are available spin labels.
A linker, also called spacers, refers to an extension of a bendable molecule or molecule that can be used to join two molecules of interest, such as a fluorophore attached to one or two peptide molecules. Depending on the design and application, Creative Peptides can insert the appropriate linker between the tags, proteins or fluorophores and peptides. Including but not limited to the following services.
Fluorescent and dyes labeled peptides are commonly used in protein binding or localization studies. These labels can be incorporated into fluorescent peptides or labeled peptides at many locations. Usually, they are incorporated into the N-terminal or Cys/Lys side chain. We can construct any feasible fluorescent peptides according to your requirements.
Biotin is usually attached to the N-terminal or C-terminal, and the N-terminal biotinylation can be carried out directly on the primary amino group, while the biotinylation is usually carried out on the ε-amino group of C-terminal lysine. Creative Peptides routinely synthesizes peptides with the biotin tags.
Tags fused into the target protein can increase the expression level, solubility, folding, purification, and detection of the recombinant protein. The most commonly used small peptide tags are Flag, HA, His, Myc.
Radioactive labeling
Radioactive isotopes, such as 3H (tritium) or 125I (iodine-125), can be incorporated into peptides for various research purposes including receptor binding studies, ligand-receptor interaction assays, and radioimmunoassays.
Phosphorylation is a critical post-translational modification that regulates many cellular processes. Peptides can be labeled with phosphate groups (e.g., phospho-tyrosine, phospho-serine, phospho-threonine) to mimic phosphorylated proteins and study signaling pathways or kinase activity.
Acetylation and methylation are common modifications on lysine and arginine residues, respectively. Peptides can be labeled with acetyl or methyl groups to mimic these modifications and investigate their effects on protein function, localization, and interactions.
Glycosylation is a common post-translational modification that plays crucial roles in protein folding, stability, and function. Peptides can be labeled with glycans or glycosaminoglycans to study glycoprotein interactions, receptor-ligand binding, and immune responses.
PEG (polyethylene glycol) can be attached to peptides to increase their solubility, stability, and circulating half-life in vivo. Pegylated peptides are used in drug delivery systems, diagnostics, and therapeutic applications.
Peptides can be labeled with metal chelators such as EDTA or DOTA for chelating metal ions like copper, gadolinium, or technetium. These metal-labeled peptides are employed in molecular imaging, MRI contrast agents, and targeted therapy.
Click chemistry reactions, like copper-catalyzed azide-alkyne cycloaddition (CuAAC) or strain-promoted azide-alkyne cycloaddition (SPAAC), can be used to label peptides with various functional groups or fluorophores with high specificity and efficiency.
FAQ
1. What are the advantages of peptide labeling?
Peptide labeling enhances the detectability of peptides in complex biological samples, enabling precise localization, quantification, and tracking of their behavior. It facilitates a wide range of research applications such as cellular imaging, drug delivery, and biomarker discovery.
2. What labeling options do you offer?
We offer fluorescent labeling with a variety of dyes, radioactive labeling using isotopes like 3H, 14C, or 125I, biotinylation for affinity purification, and custom chemical modifications tailored to your specific requirements.
3. How do you ensure the integrity of the labeled peptides?
We employ stringent quality control measures throughout the labeling process to ensure the integrity and functionality of the peptides. Our experienced team utilizes optimized protocols and high-quality reagents to minimize any potential degradation or loss of activity.
4. Can you handle peptides of different lengths and sequences?
Yes, our labeling services are compatible with peptides of various lengths, sequences, and modifications. Whether you require labeling for short peptides, peptide fragments, or modified peptides, we can accommodate your needs.
5. What is the turnaround time for peptide labeling services?
The turnaround time depends on the specific requirements of your project, including the labeling method, peptide characteristics, and desired quantity. We strive to provide efficient and timely service, and our team will work closely with you to meet your deadlines.
6. What types of applications can benefit from peptide labeling?
Peptide labeling is widely used in various biomedical research applications, including cellular imaging, protein-protein interaction studies, drug discovery, pharmacokinetics, and biomarker identification. It enables researchers to visualize and analyze the behavior of peptides in biological systems with high precision and sensitivity.
References
- Yan, F., et al. Photo-assisted peptide enrichment in protein complex cross-linking analysis of a model homodimeric protein using mass spectrometry. Proteomics. 2011, 11(20): 4109-4115.
- Smirnova, T. I.; Smirnov, A. I. Peptide-membrane interactions by spin-labeling EPR. In Methods in Enzymology. 2015: 564: 219-258.
