Stapled Peptide Synthesis

Stapled peptides are a rapidly emerging class of new-generation drugs that combine the synthetic manipulability and cell penetration of small molecules with the three-dimensionality and versatile target recognition capabilities of biologics. With decades of hands-on experience in peptide synthesis and research, CD Formulation has developed specific skills and expertise that enable it to produce stapled peptides of superior quality. We have extensively developed hundreds of stapled peptides and can produce any stapled peptide according to your structural design needs.

What is Stapled Peptide?

Stapled peptides are short peptides with a typical α-helical conformation that are constrained by a synthetic stapler or scaffold. A stapler is a covalent link between two amino acid side chains that form a peptide macrocycle. The introduction of a synthetic scaffold (staple) can lock the peptide into a specific conformation to reduce conformational entropy. This approach can increase target affinity and cell penetration and prevent proteolytic degradation, thus making it an ideal approach to overcome the limitations of small molecules and protein biologics in targeting protein-protein interactions (PPIs) within cells. Small molecules are usually limited to proteins with specific features on their surfaces, and most protein biologics cannot penetrate cells. Stapled peptides have a locked α-helical structure (the most common protein secondary structure) that can easily penetrate cells. Although there are various strategies to constrain α-helices, whether non-covalent or covalent stabilization techniques. All-hydrocarbon covalent attachment of peptide staples has been shown to improve stability and cell penetration. Peptide staples are usually synthesized by ring-closing metathesis (RCM).

Fig. 1 Stapled peptide architectures. (Tan YS, et al., 2016)

Explore Our Custom Stapled Peptide Synthesis Services

At CD Formulation, our team of peptide synthesis experts has the expertise and specific skills to design and synthesize high-quality stapled peptides for a variety of applications based on your needs.

Our scientists are familiar with a variety of synthesis techniques, including solid-phase peptide synthesis (SPPS), liquid-phase peptide synthesis (LPPS), and chemo-enzymatic peptide synthesis (CEPS), allowing us to select the most appropriate technology to support each individual peptide synthesis project. At the same time, we strictly follow quality control standards to ensure that we provide you with high-purity, low-impurity peptide products.

Our stapled peptide synthesis services include but are not limited to the following:

Stapled Peptide Synthesis

We usually use the Fmoc-solid phase peptide synthesis method to prepare stapled peptides. First, two α-methyl and α-olefin non-natural amino acids are introduced during the solid phase synthesis of the polypeptide chain. Then, an olefin metathesis reaction (RCM) occurs between the two non-natural amino acids to cyclize to form a full-carbon scaffold with a stable α-helical structure conformation, thereby synthesizing the stapled peptide.

Stapled Peptide Labeling

If required, we also provide stapled peptide labeling services, including fluorescent labeling and biotin labeling.

• Fluorescent Labeling

N-terminal fluorescent labeling is the most common fluorescent labeling. We provide high-quality fluorescent labeling services by conjugating fluorescence to the N-terminus, C-terminus, or side chains of cysteine or lysine residues of stapled peptides to generate specific fluorescent labeled peptides for in vivo biomedical imaging, protein binding, and localization studies, etc.

• Biotin Labeling

Biotin labeling is used for biophysical characterization and assessment of target interactions in vitro. Our experts use affinity tags to detect appropriately labeled peptides (e.g. using antibodies) or to separate labeled peptides from unlabeled peptides.

Our Synthetic Strategies for Stapled Peptides

Hydrocarbon stapled peptides are peptides locked in a biologically active α-helical conformation by site-specific introduction of an all-hydrocarbon stapled peptide. Our team of peptide experts utilizes the following key technologies to prepare stapled peptides.

Preparation of Stapled Peptides Using Ring-Closing Metathesis Reaction

The all-hydrocarbon α-helical staples combine two different conformational stabilization strategies to induce α-helical structures, namely α,α-disubstitution and macrocyclic bridge formation. During solid-phase peptide synthesis, α-methyl and α-alkenylglycine cross-linking amino acids are incorporated at appropriate positions. The resin-bound peptides are treated with Grubbs I olefin metathesis catalyst to generate cross-links between the two unnatural amino acids, thereby forming stapled peptides supported in α-helical conformation. Two different hydrocarbon staples are included, reflecting the stable α-helical structure in the peptides.

Fig. 2 Example of ring closing metathesis stapling. (Moiola M, et al., 2019)

Preparation of Stapled Peptides Using Click Chemistry

Click chemistry is an efficient and highly selective chemical reaction that is often used to synthesize complex molecules, including biomacromolecules such as peptides. In the process of synthesizing stapled peptides, the "azido-alkyne" click chemistry reaction can be used as an effective method to connect different amino acids or peptides. The reaction is highly efficient and has mild conditions, and triazole-stapled peptides can be easily synthesized.

Fig. 3 Cu(I)-catalysed azidealkyne cycloaddition.(Tan YS, et al., 2016)

Peptide Manufacturing & Analytical Services

In addition to peptide synthesis capabilities, CD Formulation combines flexible GMP manufacturing facilities with cutting-edge peptide analytical knowledge to provide a full range of quality control testing services to accelerate the commercialization of your products, including:

Publication

CD Formulation's stapled peptide synthesis services are tailored to meet the specific needs of researchers and organizations seeking high-quality peptides for drug discovery, vaccine development, diagnostics, and other scientific endeavors. Please don't hesitate to contact us if you are interested in our services. We look forward to cooperating with you.

How It Works

STEP 1

Submit a service request describing your specific research or development need.

STEP 2

We'll email you to provide your quote and confirm order details if applicable.

STEP 3

Execute the project with real-time communication, and deliver the final report promptly.