An Introduction to Peptide Synthesis

The field of custom peptide synthesis has seen remarkable progress since Advanced ChemTech’s founding in 1985. Peptides have become one of the most important biological phenomena for developing novel therapeutics. 

For research and pharma labs, peptide synthesis is vital in drug discovery, receptor binding studies, peptide vaccines, and much more. This post will introduce you to the fascinating world of peptides. 

From simple definitions to complex analysis of concepts like solid phase peptide synthesis, this article will serve as a comprehensive guide to peptide synthesis. It should help you appreciate the importance of peptides in pharmaceutical studies. 

What Are Peptides?

Peptides are organic molecules consisting of two or more amino acids with a carboxyl group on one end and an amine group on the other. Peptide bonds fuse the amino acids together in chains scientifically known as polypeptides. Here’s more on what peptides are.

Peptides are similar to proteins but differ in size and structure, containing between two and 50 amino acids. In contrast, proteins carry over fifty, running to hundreds or thousands of amino acids. In most cases, peptides are classified based on their number of amino acids. 

Peptides play important roles in the body’s functions, such as:

  • Hormone production.
  • Immune response.
  • Cell signaling and communication.
  • Enzyme production.
  • Transport of molecules within the body.

Here’s more on what peptides are actually used for.

A Little More on Peptide Structures

Scientists classify peptides into four main categories based on their structure: linear, branched, cyclic, and stapled. Each type has its unique properties and functions in the body.

  • Linear peptides consist of amino acids linked together in a straight chain. Their simple structure makes it easy for scientists to synthesize them in the laboratory for research purposes.
  • Branched peptides, also known as dendrimers, have multiple branching points in their structure. These branches can increase the stability and solubility of the peptide, making them useful for drug delivery and targeting specific tissues or cells.
  • Cyclic peptides form a ring-like structure because of a covalent bond that pulls together the two amino acids at each end of the chain. This unique structure makes cyclic peptides resistant to degradation by enzymes in the body, making them suitable for therapeutic use.
  • Stapled peptides are a newer class of peptides where a small chemical “staple” links two amino acids within the chain. This modification can enhance stability and binding affinity, making stapled peptides promising drug candidates for treating diseases.

The alternative classification, including the length of peptides, is as follows:

  • Dipeptides: two amino acids linked together.
  • Tripeptides: three amino acids linked together.
  • Oligopeptides: 4-20 amino acids linked together.
  • Polypeptides: more than 20 amino acids linked together.

What Is Peptide Synthesis?

Peptide synthesis is the process of building peptides in a laboratory setting. It involves linking individual amino acids to form longer chains, which can then be folded and modified to create different peptide structures.

But scientists didn’t invent peptide synthesis; they just found a way to do it in a controlled and reproducible manner. In fact, peptide synthesis occurs naturally in living organisms, where peptides play important roles in various biological processes.

Natural peptide synthesis begins with the transcription of DNA into messenger RNA (mRNA). Then, ribosomes read the mRNA and cause amino acids to fuse in a polypeptide chain, following a sequence with desired physiological effects. Enzymes then fold and modify this chain, forming a functional peptide.

In contrast, synthetic peptide synthesis involves assembling these amino acids step-by-step using various chemical reactions. One common strategy is solid-phase peptide synthesis, in which the peptide chain is built on a solid support, and each amino acid is added in a specific order.

In a later section, we’ll discuss more details of peptide synthesis methods, but let’s first discuss its impetus.

Why Do Scientists Perform Peptide Synthesis?

Peptides are essential for critical biological processes, including cell signaling, enzyme function, and immune responses. Therefore, synthetic peptide synthesis holds great potential for pharmaceutical applications.

One major advantage of synthetic peptides is their high specificity and selectivity. Scientists can design peptides that bind to particular receptors or enzymes in the body by targeting specific amino acid sequences. It potentially offers more precise and targeted treatments without most of the side effects associated with traditional drugs. 

Furthermore, synthetic peptides also allow for modifications in their chemical structure, enhancing their stability, solubility, and bioavailability. This flexibility allows scientists to optimize the peptide’s properties for specific applications, such as:

  • Improving its ability to cross the blood-brain barrier.
  • Increasing its half-life in the body. 
  • Enhancing its potency and efficacy.

Moreover, synthetic peptides also offer a cost-effective alternative to traditional drugs. With advancements in peptide synthesis methods, producing large quantities of peptides at a lower cost has become easier and faster.

Additionally, synthetic peptides have also found applications in research and diagnostics. Scientists can study their interactions with other molecules by synthesizing specific peptides. 

Such knowledge presents fertile grounds for identifying potential drug targets and developing new diagnostic tools.

The Fundamentals of Solid Phase Peptide Synthesis (SPPS)

Peptide synthesis involves artificially producing peptides, which are short chains of amino acids. Robert Bruce Merrifield developed solid-phase peptide synthesis (SPPS) in the 1960s.

The Key Components and Reagents Involved in SPPS

The key components and reagents used in the process are:

  • Amino acids: These protein building blocks are necessary for peptide synthesis as they determine the sequence and structure of the resulting peptide.
  • Protecting groups: These reagents help protect specific functional groups of amino acids during the synthesis process.
  • Resins: These solid supports are necessary for SPPS and allow for better control over the reaction.
  • Coupling reagents: These reagents facilitate the attachment of amino acids to the growing peptide chain.
  • Deprotecting reagents: These are used to remove protecting groups from amino acids after coupling reactions.

The Steps Involved in Peptide Synthesis

The general steps involved in peptide synthesis are as follows:

  1. Activation: The first step involves activating the resin by attaching a linker molecule, which allows for the attachment of the growing peptide chain.
  2. Coupling: Amino acids are added one by one using coupling reagents to form peptide bonds.
  3. Deprotection: Deprotecting reagents remove protecting groups from amino acids after each coupling reaction.
  4. Washing: The resin is washed between steps to remove any excess reagents and by-products.
  5. Cleavage: Once the desired peptide chain is synthesized, it is cleaved from the resin using a cleaving agent.
  6. Purification: The crude peptide product is then purified using various techniques, such as chromatography, to obtain a pure peptide.

Advantages of SPPS

Solid-phase peptide synthesis (SPPS) has numerous advantages compared to other peptide synthesis methods. Some of these include:

  • High purity: Since each step in SPPS involves purification, the final product is usually high purity.
  • Efficiency: Using solid supports and protecting groups allows for better control over the reaction, resulting in higher yields and fewer side reactions.
  • Automation: SPPS can be automated, allowing for the synthesis of multiple peptides simultaneously.
  • Versatility: SPPS is compatible with a wide range of amino acids, so it’s possible to synthesize diverse peptides.
  • Cost-effective: SPPS is a cost-effective peptide synthesis method thanks to its efficiency and automation.

Applications of SPPS

The ability to synthesize peptides with high purity and efficiency has made SPPS an essential technique in various fields, including:

  • Pharmaceuticals: Peptides have gained significant interest in the pharmaceutical industry due to their high specificity and low toxicity. SPPS allows for synthesizing peptides with specific sequences that can be used in drug discovery and development.
  • Biotechnology: SPPS is widely used to produce custom-made peptides for various applications, such as enzyme production, biomaterials, and diagnostics.
  • Protein engineering: The ability to control the sequence of amino acids makes SPPS a valuable tool in protein engineering. Peptides synthesized using SPPS can be used to study protein structure and function.
  • Research: SPPS is an essential technique in peptide research, allowing for synthesizing peptides to study biological processes and develop new therapies.

Custom Peptide Synthesis

Custom peptide synthesis simply means synthesizing a specific sequence of amino acids, usually for research or industrial purposes. SPPS is the most commonly used method due to its efficiency, cost-effectiveness, and versatility.

At Advanced ChemTech, we support manufacturers and researchers in the biotechnology and pharmaceutical industries with custom peptide synthesis services. We synthesize high-quality, custom peptides for a wide range of applications.

Final Thoughts on Peptide Synthesis 

The need to understand proteins and their functions has led to developing peptide synthesis techniques like SPPS. This technology has revolutionized the field of biochemistry and molecular biology, allowing scientists to study, manipulate, and create peptides with unprecedented precision.

Custom peptide synthesis will advance thanks to its vast potential and continuous research. It will enable the creation of novel peptides with unique properties for specific applications, promoting growth and innovation in biotechnology and medicine. 

Advanced ChemTech is the right place to buy peptides. We combine decades of experience, top-of-the-line equipment, and exceptional customer service to deliver high-quality custom peptides that meet your specific needs. 

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