Peptide Structure Modification


ALL Chemistry has provided high-quality peptide synthesis, peptide library customization and array services for years. We deliver satisfaction through sustained customer focus from inquiry to delivery and use of our reagents and services. 


Introduction of Peptide Structure Modification


Peptides are usually the original source of many lead compounds. However, its poor stability towards protein enzymes and insufficient receptor binding ability due to its flexible conformation limit its extensive application. Therefore, structure modification of classical peptides becomes a preferable way for drug research and development. Peptide structure modification refers to the process of altering the composition and arrangement of amino acids within a peptide molecule. Peptides are short chains of amino acids linked together by peptide bonds, and they play a crucial role in various biological processes. By modifying the structure of peptides, researchers aim to enhance their stability, activity, and specificity, thereby expanding their potential applications in fields such as medicine, biotechnology, and materials science. SB-PEPTIDE can conjugate and functionalize peptides with many different compounds. Affinity tags can have biotin, maleimide, alkyne, azide, or thiol functions. These functions serve for bioconjugations, in this case between a peptide and something else.

Peptides can be modified at various positions, including the free N-terminal amine group, side chains of some normal or modified amino acids, or the C-terminal carboxylic group. The N-terminal extremity allows many modifications quite easily. The C-terminal extremity is generally more challenging to modify than the N-terminal extremity. The easiest alternative is to add an extra Lysine in the C-terminal position, which can be labeled in the side chain. Internal modifications consist generally of adding the conjugate of interest on the side chain of lysine, asparagine, serine, threonine, or modified amino acids. In any case, the modification of a peptide can modify its properties and, for example, decrease its bioactivity. This is hardly predictable and has to be tested. This area of study involves techniques such as chemical synthesis, enzymatic modification, and genetic engineering, which allow for the precise manipulation of peptide structures to achieve desired properties and functionalities. Peptide structure modification holds great promise for the development of novel therapeutics, diagnostics, and biomaterials that can address a wide range of biological challenges and improve human health.

Fig.1 Biosynthesis of lanthipeptides


Types of Peptide Structure Modification


Four protein chemical targets account for the vast majority of cross-linking and chemical modification technologies:

-- Primary Amines (–NH2): This group exists at the N-terminus of each polypeptide chain and in the side chain of lysine (Lys, K) residues. The introduction of primary amines into peptide structures allows for the attachment of various functional groups, enabling the creation of peptide conjugates with enhanced properties.

-- Carboxyls (–COOH): This group exists at the C-terminus of each polypeptide chain and in the side chains of aspartic acid (Asp, D) and glutamic acid (Glu, E). Modification of carboxyl groups in peptides can be achieved through esterification, amidation, or peptide coupling reactions. These modifications can improve peptide stability, increase solubility, or enable the attachment of other molecules for targeted drug delivery.

-- Sulfhydryls (–SH): This group exists in the side chain of cysteine (Cys, C). Modification of sulfhydryls can be achieved through thiol-disulfide exchange reactions, allowing for the creation of disulfide bridges or the attachment of other molecules. Disulfide bridges can enhance peptide stability and provide a controlled release of therapeutic agents.

-- Carbonyls (–CHO): These aldehyde groups can be created by oxidizing carbohydrate groups in glycoproteins. Modification of carbonyls in peptides can be accomplished through various chemical reactions, including reduction, oxidation, or condensation. These modifications can alter peptide conformation, stability, or reactivity.

For each of these protein functional-group targets, there are one to several types of reactive groups that are capable of targeting and have been used as the basis for synthesizing cross-linking and modification molecules.


Peptide Structure Modification Services at ALL Chemistry


Chemical modification of proteins is an important tool for probing natural systems, creating therapeutic conjugates and generating novel protein constructs. Site-selective reactions require exquisite control over both chemoselectivity and regioselectivity, under ambient, aqueous conditions. ALL Chemistry offers hundreds of peptide modifications to meet your custom peptide needs. These peptide modifications can be used to create synthetic peptide with the exact conformation or characteristics needed for specific applications. Large numbers of modified amino acids are focused on post-translation modifications (PTM) that naturally occur in vivo, while others are pharmacologically modified or stable isotope labeled. Additionally, tags, proteins or oligonucleotides can be chemically conjugated to these peptides through Bio-Synthesis. With our rich experience in providing modified peptide synthesis, we are your best choice for producing custom-modified peptides on time and on budget. We deliver satisfaction through sustained customer focus from inquiry to delivery and use of our reagents and services. Please contact us if you require any peptide modifications.


Service Specification: 


whole protein modification and labeling service item

N terminus Modification

Isotope labeling

C terminus Modification

Multiple Antigen Proteins (MAPs) & Carrier Proteins Labeling

Fluorescence/Dye Labeling

Paramagnetic Labels

Quenched Fluorescent Peptide Labeling

Spacers and Linkers Modification

Quantum Dots Labels

BSA, KLH and OVA Conjugation

N-Methyl Amino Acids Labeling

Homo Amino Acid Labeling


Advantages of Our Services


Provide quality-guaranteed products, all products are provided with a quality analysis report (COA), use advanced instruments such as MS (Mass Spectrometry), HPLC and NMR (Nuclear Magnetic Resonance) for quality inspection.

Development of therapeutic peptides using different glycosylation strategies

Professional and reliable packaging ensures the safety and stability of products from transportation, storage to use.

Deep knowledge and rich experience in biomaterial modification and conjugation. ALL Chemistry has a dedicated team of glycan experts to deal with complex carbohydrate research.

With fast, economical, and efficient customized peptide structure modification products, ALL Chemistry will forever provide customers with cost-effective and perfect after-sales service.


Project Workflow


Evaluation → Experiment Design → Formal Quotation → Peptide Structure Modification → Results → Delivery


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