Creative Peptides is committed to making contributions to biopharmaceutical research, specializing in providing amino acid products. Our products are designed to meet the different needs of the global audience, and at the same time achieve unparalleled outstanding achievements in the biomedical field.
What are Amino Acids?
Amino acids are the building blocks of proteins, which are essential macromolecules for life. They play crucial roles in various biological processes, including the formation of structural components, enzyme function, and signaling within cells. Amino acids, as the basic "building blocks" of life, are a class of organic compounds that contain both an amino group and a carboxyl group. They are also the fundamental components of proteins. The general structure formula is RCH(NH2)COOH, where the central carbon atom is bonded to an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom (-H), and a unique side chain group (R group). It is this R group, like a magical wand, that creates the differences between various amino acids. Different R groups have distinct chemical properties and spatial structures, which lead to the wide variety of amino acids, each with its own characteristics. These differences give amino acids diverse functions, playing an indispensable role in biological processes and laying the foundation for the complexity and diversity of life.
Amino Acid Structure

Amino acids are organic compounds characterized by having both an amino group (-NH2) and a carboxyl group (-COOH) attached to a central carbon atom, known as the alpha carbon. Additionally, they have a variable side chain, denoted as R group, which determines the specific properties of each amino acid.
Amino Acid Properties
Amino acids have unique physical properties. They typically appear as colorless crystals or powders, with high melting points, most of which are above 200°C. In terms of solubility, they can dissolve in strong acid or strong alkali solutions but are poorly soluble in organic solvents like ethanol and ether.
Chemically, amino acids exhibit amphoteric dissociation characteristics. Since the molecule contains both the basic amino group and the acidic carboxyl group, dissociation occurs under different pH conditions. The pH of the solution when the net charge of the amino acid is zero is known as the isoelectric point. By utilizing the amphoteric dissociation and isoelectric point properties of amino acids, practical applications can achieve their separation, purification, and analysis by adjusting the pH of the solution. For example, in electrophoresis techniques, the movement of amino acids in an electric field can be used to identify and analyze them, providing strong support for life science research and the development of related industries.
Classification of Amino Acids
- By polarity
Polar amino acids (e.g., serine, glutamic acid) and nonpolar amino acids (e.g., leucine, isoleucine). - By acidity or basicity
Acidic amino acids (e.g., glutamic acid), basic amino acids (e.g., lysine), and neutral amino acids (e.g., glycine).
- By chemical structure
Aliphatic amino acids, aromatic amino acids, heterocyclic amino acids, and so on. - By a nutritional perspective
Amino acids can be classified into essential amino acids and non-essential amino acids.
Amino Acids Chart
There are only 20 amino acids in the genetic code, and the 20 animo acids can be classified in many ways. They can be classified according to polarity (polar amino acids and no polar amino acids), pH level, and the type of side chain group, such as aliphatic, aromatic, containing hydroxyl or sulfur, etc. The amino acids reference charts are as follows.
20 amino acids structures and names.pdf
Hydrophobic Amino Acids
Amino Acids with Hydrophobic Side Chain – Aliphatic
Amino Acids with Hydrophobic Side Chain – Aromatic
Polar Amino Acids
Amino Acids with Polar Neutral Side Chains
Amino Acids with Electricaly Charged Side Chains – Acidic
Amino Acids with Electricaly Charged Side Chains – Basic
Unique Amino Acids
Properties of Common Amino Acids
Properties of Common Amino Acids
3-Letter Symbol | 1-Letter Symbol | Name | Side Chains | Molecular Formula | CAS.No | Molecular weight | PI | PKa | PKb | R Group |
---|
Gly | G | Glycine | Hydrophilic | C2H5NO2 | 56-40-6 | 75.07 | 6.06 | 2.4 | 9.8 | -H |
Ala | A | Alanine | Hydrophobic | C3H7NO2 | 56-41-7 | 89.09 | 6.11 | 2.4 | 9.9 | -CH₃ |
Val | V | Valine | Hydrophobic | C5H11NO2 | 72-18-4 | 117.2 | 6 | 2.4 | 9.7 | -CH-(CH3)2 |
Leu | L | Leucine | Hydrophobic | C6H13NO2 | 61-90-5 | 131.2 | 6.01 | 2.3 | 9.7 | -CH2-CH(CH3)2 |
Ile | I | Isoleucine | Hydrophobic | C6H13NO2 | 73-32-5 | 131.2 | 6.05 | 2.3 | 9.8 | -CH(CI3)-CI2-CI3 |
Phe | F | Phenylalanine | Hydrophobic | C9H11NO2 | 63-91-2 | 165.2 | 5.49 | 2.2 | 9.3 | -CH2-C6H5 |
Trp | W | Tryptophane | Hydrophobic | C11H12N2O2 | 73-22-3 | 204.2 | 5.89 | 2.5 | 9.4 | -C8NH6 |
Tyr | Y | Tyrosine | Hydrophobic | C9H11NO3 | 60-18-4 | 181.2 | 5.64 | 2.2 | 9.2 | -CH2-C6H4-OH |
Asp | D | Asparagine | Acidic | C4H7NO4 | 6899-03-2 | 133.1 | 2.85 | 2 | 9.9 | -CI2-COOH |
Asn | N | Aspartic acid | Hydrophilic | C4H8N2O3 | 70-47-3 | 132.1 | 5.41 | 2.1 | 8.7 | -CI2-CONH2 |
Glu | E | Glutamic acid | Acidic | C5H9NO4 | 56-86-0 | 147.1 | 3.15 | 2.1 | 9.5 | -(CH2)2-COOH |
Lys | K | Lysine | Basic | C6H14N2O2 | 56-87-1 | 146.2 | 9.6 | 2.2 | 9.1 | -(CH2)4-NH2 |
Gln | Q | Glutamine | Hydrophilic | C5H10N2O3 | 56-85-9 | 146.2 | 5.65 | 2.2 | 9.1 | -(CH2)2-CONH2 |
Met | M | Methionine | Hydrophobic | C5H11NO2S | 63-68-3 | 149.2 | 5.74 | 2.1 | 9.3 | -(CI2)-S-CI3 |
Ser | S | Serine | Hydrophilic | C3H7NO3 | 56-45-1 | 105.1 | 5.68 | 2.2 | 9.2 | -CI2-OH |
Thr | T | Threonine | Hydrophilic | C4H9NO3 | 72-19-5 | 119.1 | 5.6 | 2.1 | 9.1 | -CH(CI3)-OH |
Cys | C | Cysteine | Hydrophilic | C3H7NO2S | 52-90-4 | 121.2 | 5.05 | 1.9 | 11 | -CI2-SH |
Pro | P | Proline | Hydrophobic | C5H9NO2 | 147-85-3 | 115.1 | 6.3 | 2 | 11 | -C3H6 |
His | H | Hlstidine | Basic | C6H9N3O2 | 71-00-1 | 155.2 | 7.6 | 1.8 | 9.3 | |
Arg | R | Argnine | Basic | C6H14N4O2 | 74-79-3 | 174.2 | 10.8 | 1.8 | 9 | |
PI is the pH of the isoelectric point
PKa is the negative of the logarithm of the dissociation constant for the -COOH group
PKb is the negative of the logarithm of the dissociation constant for the –NH3+ group
Amino Acids with Hydrophobic Side Chain - Aliphatic
Amino Acids with Hydrophobic Side Chain – Aromatic
Amino Acids with Polar Neutral Side Chains
Amino Acids with Electricaly Charged Side Chains – Acidic
Amino Acids with Electricaly Charged Side Chains – Basic
Unique Amino Acids
Biological Functions of Amino Acids
Protein synthesis
Amino acids are the building blocks of proteins. During protein synthesis, amino acids are linked together through peptide bonds to form polypeptide chains, which then fold into specific three-dimensional structures to perform various functions in the body.
Enzyme function
Many enzymes, which are biological catalysts that facilitate biochemical reactions in the body, are proteins composed of amino acids. The specific sequence and arrangement of amino acids in enzymes determine their catalytic activity and substrate specificity, allowing them to accelerate chemical reactions necessary for metabolism, digestion, and other physiological processes.
Neurotransmitter synthesis
Amino acids serve as precursors for the synthesis of neurotransmitters, which are chemical messengers involved in transmitting signals between neurons (nerve cells) in the nervous system. For example, the neurotransmitters serotonin, dopamine, and gamma-aminobutyric acid (GABA) are synthesized from specific amino acids (tryptophan, tyrosine/phenylalanine, and glutamate, respectively).
Hormone regulation
Some amino acids are involved in the synthesis of hormones, which are signaling molecules that regulate various physiological processes in the body. For instance, thyroid hormones (thyroxine and triiodothyronine) contain the amino acid tyrosine, while insulin, a hormone that regulates blood sugar levels, consists of two polypeptide chains linked by disulfide bonds, which are formed between cysteine residues.
What do Amino Acids do?
Pharmaceuticals
Amino acids serve as the foundation for synthesizing pharmaceuticals. They are used in the production of antibiotics, vaccines, and various medications. For example, antibiotics like penicillin are produced from amino acids.
Medical applications
Amino acids have medical applications beyond pharmaceuticals. They are used in intravenous (IV) solutions for patients who cannot consume nutrients orally. Amino acids are also used in wound healing and tissue repair.
Food industry
Amino acids are used as flavor enhancers and additives in the food industry. Monosodium glutamate (MSG), derived from glutamic acid, is a common flavor enhancer. Amino acids also play a role in fermentation processes, such as in brewing and winemaking.
Cosmetics and personal care products
Amino acids are used in cosmetics and personal care products for their moisturizing and conditioning properties. They can help improve skin texture, promote hair health, and enhance the effectiveness of skincare products.
Agriculture
Amino acids are used in agriculture as fertilizers to improve soil quality and promote plant growth. They are also used in animal feed to enhance growth and productivity in livestock.
Biotechnology and research
Amino acids are essential in biotechnology for protein engineering and the production of recombinant proteins. They are also used as markers in biochemical research and as standards in analytical chemistry techniques like chromatography.
Textile industry
Amino acids are utilized in the production of synthetic fibers like nylon. These fibers are used in textiles, carpets, and industrial applications due to their strength and durability.
Biodegradable polymers
Amino acids are used in the production of biodegradable polymers, which have applications in packaging materials, biomedical implants, and environmentally friendly plastics.
Amino Acids in Cell Culture
Amino acids are essential nutrients for cell cultures. Most animal cells in culture require a source of amino acids, which are the building blocks of proteins in cells. Most commonly used media for mammalian cell culture contains all 20 standard amino acids, including essential amino acids that cannot be synthesized by cells and must be provided in the medium. Amino acid composition and concentration in the medium can influence cell growth and productivity. Therefore, the optimization of amino acid concentrations in the culture medium is an important aspect of cell culture process development.
Supplementing cell culture media with specific amino acids can improve cell growth and protein production. For example, glutamine is a commonly supplemented amino acid due to its role in protein synthesis and energy production. However, glutamine can rapidly degrade in culture medium, leading to the release of toxic ammonia. To overcome this challenge, a more stable form of glutamine, alanyl-glutamine, is commonly used in cell culture.
Unnatural Amino Acids for Peptide Synthesis
Unnatural amino acids are synthetic or modified amino acids that are not naturally found in proteins. They are often used in peptide synthesis to introduce specific properties or functionalities into peptides, which can be useful in various research and medical applications. Here are some common types and uses of unnatural amino acids in peptide synthesis:
Fluorescent amino acids
These amino acids contain fluorescent groups that emit light upon excitation. They are widely used in studying protein-protein interactions, protein localization, and dynamics.
Photoactivatable amino acids
These amino acids contain groups that can be activated by light to undergo chemical reactions. They are used in studying protein function, protein-protein interactions, and mapping protein-protein interfaces.
Crosslinking amino acids
Amino acids with reactive groups that can form covalent bonds with nearby amino acids are used for crosslinking peptides or proteins. This helps in studying protein structure, protein-protein interactions, and stabilizing protein complexes.
Bioorthogonal amino acids
These amino acids have functional groups that react selectively with each other in the presence of other biomolecules. They are useful for labeling proteins in complex biological environments.
Chemical modification amino acids
Amino acids with specific chemical functionalities can be incorporated into peptides to introduce post-translational modifications or to facilitate conjugation with other molecules.
Structurally modified amino acids
Amino acids with modified side chains or backbone structures can be used to stabilize peptide conformations, enhance protease resistance, or modulate peptide-receptor interactions.
Diverse functional groups
Unnatural amino acids can be designed with a wide range of functional groups such as azides, alkynes, ketones, and aldehydes, which can be used for various bioconjugation strategies.
Optically active amino acids
Amino acids with chiral centers can be synthesized in optically pure forms, enabling the synthesis of peptides with defined stereochemistry for studying structure-activity relationships.
By incorporating these unnatural amino acids into peptides, researchers can tailor the properties and functions of peptides for specific applications in drug discovery, diagnostics, materials science, and chemical biology.
FAQs
1. What types of amino acid products do you offer?
We offer a comprehensive range of amino acid products, including individual amino acids, amino acid mixes, custom formulations, and specialty amino acids tailored to specific research needs.
2. Are your amino acid products suitable for cell culture?
Yes, our amino acid products are specifically designed for cell culture applications. They are highly purified and free from contaminants, making them ideal for supporting cell growth and proliferation.
3. Do you provide certificates of analysis (COA) for your products?
Absolutely. We provide detailed certificates of analysis with each batch of our amino acid products, documenting their purity, composition, and quality control testing results.
4. What is the shelf life of your amino acid products?
Our amino acid products are manufactured under strict quality control conditions to ensure maximum stability and shelf life. Typically, our products have a shelf life of at least two years when stored according to the provided instructions.
5. Can you provide custom formulations of amino acids?
Yes, we offer custom formulation services to meet your specific research requirements. Whether you need a unique amino acid mix or a specialized formulation, our team of experts can work with you to develop a product tailored to your needs.
6. Are your amino acid products suitable for in vivo studies?
While our amino acid products are primarily designed for in vitro applications such as cell culture, we can provide specially formulated products for in vivo studies upon request. Please contact us to discuss your specific needs.
7. What quality control measures do you have in place for your amino acid products?
We adhere to stringent quality control measures throughout the manufacturing process to ensure the purity, consistency, and integrity of our amino acid products. This includes rigorous testing for contaminants, verification of composition, and adherence to industry standards.

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