General Peptide Information

What is a peptide?

Peptides are nifty little tools in immunology, proteomics, and cell biology. JPT, as one of the largest provider custom peptide formats and having the most extensive catalog products, prides itself in its peptide expertise. But before diving into that world and their research applications, it is crucial to understand the basics. 

Falling into the category of biological polymers, peptides can be summarized as short chains of amino acids linked via peptide (or amide) bonds. Each peptide contains an N-terminal (NH3), a C-terminal (COOH) and a residue bound to a central carbon. Shorter peptides are referred to as oligopeptides (2-20aa) and longer unbranched peptides chains are defined as polypeptides. The latter lay the structural foundation for proteins, and typically exceed the mass of 10 kDa. Proteins are oftentimes biologically functional in nature, and promote multiple metabolic functions within single- or multicellular organisms as ligand binding, enzymes, coenzymes, cofactors or more complex assemblies. But also simple peptides have shown to mediate many metabolic, binding, cell-penetrating or hormonal operations within and outside of a cell.

Peptide BondProteins are oftentimes biologically functional in nature, and promote multiple metabolic functions within single- or multicellular organisms as ligand binding, enzymes, coenzymes, cofactors or more complex assemblies. But also simple peptides have shown to mediate many metabolic, binding, cell-penetrating or hormonal operations within and outside of a cell. 

A protein’s functional and structural properties in its native environment are determined by its residues.


Learn more about amino acids



Naturally occurring peptides

As stated in the Handbook of Biologically Active Peptides, naturally occurring peptides are classified according under the umbrella of source and function. Some of these include, plants, fungal, and bacterial peptides, but also cancer/anticancer, vaccine, immune/inflammatory, endocrine, gastrointestinal, cardiovascular peptides. In higher organisms proteolysed peptides may function as hormones and signaling molecules. 

Assembled by enzymes or post-translationally modified by ribosomes, peptides come in all forms: linear, cyclic, and oftentimes complex. These following families consist of the most common ribosomal assembled and naturally occurring peptides:

  • Antimicrobial peptides
  • Tachykinin peptides (neuropeptides)
  • Vasoactive intestinal peptides
  • Pancreatic polypeptide-related peptides
  • Opioid peptides 
  • Calcitonin peptides
  • Self-assembling peptides
  • Other


Why use peptides?

To study a random protein’s property in immunology, proteomics, cell biology, or its binding abilities, we would ideally synthesize proteins in vitro. However, during this multiple step process, the protein is subject to many environmental influences that affect the success of its synthesis, including recombinant expression and purification, such as proteolysis, incorrect folding, formation of inclusion bodies, protein aggregation, and the lack of control on post-translational modifications, and slow process development time with lengthy purification processes. And even if synthesis and purification present itself to be successful, a protein in its native state might still be subject to external influences during a research experiment. 

This is why peptides are oftentimes the better antigens. Peptides are shorter in length (typically 8-20aa), and synthesis and purification are thus more controlled, parallelized, and reproducible, all while avoiding bacterial contamination. Moreover, peptides often provide a more detailed macromolecular view on a protein’s function, mimicking protein’s active sites, antigens, and epitopes.


Peptide Applications

With peptides being the cornerstone of so many biological processes in nature, it is not surprising they also found a broad application range in immunology, proteomics and cell biology.


Immune Monitoring , Therapy Development and Vaccinations

Keeping an eye on T and/or B cell responses and monitoring changes are crucial when tracking cancerous cells, pathogenic infections, or viral vector transfer in gene therapy. JPT has developed peptide formats that enable effective profiling of antigen-specific cellular and humoral immune responses through cellular assays like ELISPOT, flow cytometry, and antibody characterization, and mapping protein interaction sites, respectively. Moreover, to develop cell therapies and vaccines it is imperative to discover epitopes and potential drug targets in while addressing natural sequence diversity in cancerous cells and pathogens (viruses, bacteria, and parasites). 

These peptide specifications are unique to JPT and offer critical advantages for many areas of pre-clinical and clinical immunological research and development. Here we list some peptide formats: 



Neo-epitopes

One part of understanding diseases and developing a more personalized approach to them is to prioritize and monitor neo-epitopes and their formation for individualized cancer immunotherapy and peptide vaccinations.


Learn more about neo-epitopes


Proteomics

Proteomics involves the identification and quantification of a cell's protein content over time. Proteins are digested into peptides in LC/MS, as way to measure protein levels. This requires reference peptides for validation, protein biomarker identification and quantitation. For these purposes, JPT has developed a multitude of ready-to-use quantified heavy (isotope and/or Q-tag abeled) reference peptides, and PT-modified reference standards. Moreover, JPT offers MS-based standardization kits for successful assay completion:


Learn more about Proteomics

Other peptides


Peptide Specifications to consider

There are many specifications to consider when choosing our peptides. What do I need peptides for? Which format is most suitable for my experiment? Which peptide purity do I require? Do I need to consider my peptide’s solubility, stability, shefllife? What about byproducts? Find more information in our FAQs, or download our Ebook: Peptide ABC.

Check our list of products, click and go.

Get a quote