N-Terminal Modified Peptide Synthesis

Chemically synthesized peptides usually have a free amino terminus. N-terminal acetyl modification can remove the charge of the amino terminus to enhance its ability to resist enzymatic degradation by exopeptidases. CD Formulation has advanced peptide modification capabilities and can provide a variety of different N-terminal modifications to meet your various research needs.

N-Terminal Modification Necessity

The end of the peptide has a free amino acid residue, called the N-terminus or amino-terminus, which can be modified. The N-terminus can easily undergo more modifications than the C-terminus. The charge and solubility of the peptide after N-modification are reduced. In addition, N-terminal modification can increase the stability of the peptide because this modification can generate an analog of the natural protein. Therefore, this modification method can increase the biological activity of the peptide and prevent enzymatic degradation.

Fig. 1 N-terminal modification method with potential for biological applications. (Jiang HF, et al., 2022)

Explore Our Custom N-Terminal Modified Peptide Synthesis Services

As experts in peptide modification, CD Formulation provides unparalleled peptide N-terminal modification services to customers worldwide. We have reliable synthesis procedures and excellent peptide analysis technology to solve any possible challenges in the development and production of peptide therapeutics. With decades of experience in peptide modification and synthesis, our team of peptide modification experts can perform a variety of N-terminal modifications.

The following are the N-terminal modification options that CD Formulation can provide:

Acetylation	Acetylation is the process of introducing an acetyl group (-COCH₃) at the amino terminus (N-terminus) of a peptide chain. N-terminal acetylation can remove the positive charge of the polypeptide. In addition, N-terminal acetylation can increase the stability of the polypeptide against enzymatic degradation at the end of the peptide chain.
Dansyl	Dansylation refers to the process of sulfonating the amino group at the N-terminus of the peptide chain. This process usually involves the chemical modification of the amino group with a sulfonyl group (-SO₂R), where R can be hydrogen or other organic groups. Dansylated peptides are used for fluorescence-based analysis with an excitation/emission wavelength of 342 nm/562 nm.
DNP (2,4-dinitrophenyl)	DNP is commonly used as a quencher for MCA or tryptophan. This modification can be attached to the N-terminus of the peptide or as an internal modification to the lysine side chain. The purpose of DNP labeling of the N-terminus of a peptide is to improve its detectability in various analytical techniques, such as high-performance liquid chromatography (HPLC) or mass spectrometry (MS). Commonly used excitation wavelengths are 354-400nm.
MCA (7-methoxycoumarin-4-acetyl)	The advantage of MCA is its strong fluorescence properties, which facilitate fluorescence resonance energy transfer (FRET) experiments and other fluorescence detection methods. MCA-labeled peptides can be used for the localization of protein-protein interactions, enzyme activity determination, and signal transduction studies with an excitation/emission wavelength of 325/392 nm.
FITC (Fluorine Isothiocyanate)	FITC is conjugated to the N-terminus of the peptide via an aminohexanoic acid (Ahx) linker. Alternatively, an aminohexanoyl spacer can be inserted between the fluorophore and the peptide to achieve efficient N-terminal labeling. Excitation/emission wavelengths are 490/520 nm.
Biotin	Peptide biotinylation is an effective technique to bind specific peptides to streptavidin-coated surfaces. The label can be synthesized at the N-terminus or the C-terminus. Biotinylated peptides are often used in immunoassays and fluorescence-based flow cytometry.
Fatty Acid	The peptide is bound to fatty acids at the N-terminus to increase the cell permeability of the peptide. Common peptide fatty acid modifications include caprylic acid (C8), capric acid (C10), lauric acid (C12), myristic acid (C14), palmitic acid (C16), and stearic acid (C18).
Palmitoyl	Palmitoylation refers to the modification of the peptide chain by introducing palmitic acid fatty acid. This modification is usually performed by covalent bonding. Palmitoylated peptides have better biocompatibility, membrane permeability, and cell targeting.

Design Your N-Terminally Modified Peptide

When performing N-terminal modification, our peptide modification experts will focus on the following key factors to ensure that the peptide modification solution is designed to meet your needs and expected effects:

• Sequence and Structure of Peptide: Analyze the amino acid sequence of the peptide and its spatial conformation to determine the best position and method for N-terminal modification. This helps maintain the stability and function of the peptide.
• Modification Type: Select the appropriate modification type according to your specific application. For example, acetylation, phosphorylation, glycosylation, fluorescent labeling, etc., to enhance the biological activity, stability, or visualization of the peptide.
• Sequence Compatibility: Some modifications, such as aldehydes or chloromethyl ketones, may not be suitable for all peptide sequences.
• Solubility and Hydrophilicity: Consider the effect of N-terminal modification on the overall solubility and hydrophilicity of the peptide to ensure that it has good solubility in the target environment.
• Biocompatibility: Evaluate the compatibility and safety of the modified peptide in the organism to ensure that it does not cause adverse reactions.
• Functional Validation: After design, conduct necessary functional experiments to verify that the selected modification does achieve the expected effect, such as binding ability to the target, biological activity, etc.

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 has extensive experience in custom peptide synthesis with N-terminal modifications. Each synthesis step is subject to our strict quality control. Please don't hesitate to contact usif you want to learn more about the possibilities of incorporating N-terminal modification into your peptides. 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.