What are peptides and what types of benefits do they offer?
A peptide is a short chain of amino acids. Peptides are found in all living cells. The amino acids in a peptide are connected to one another in a sequence by bonds called peptide bonds. Peptides are distinguished from proteins by their shorter length, although the cut-off number of amino acids for defining a peptide and protein can be arbitrary. Traditionally, peptides are defined as molecules that consist of between 2 and 50 amino acids, whereas proteins are made up of 50 or more amino acids.
Peptides may be subdivided into oligopeptides, which have 2-20 amino acids, and polypeptides, which have a higher number of amino acids. Proteins are formed from one or more polypeptides joined together. Essentially proteins are very large peptides. In fact, some researchers use the term peptide to refer specifically to oligopeptides, or otherwise relatively short amino acid chains, with the term polypeptide being used to describe proteins, or chains of 50 or more amino acids.
Certain types of peptides play key roles in regulating the activities of other molecules. Among cells, peptides can perform various biological functions. For example, some peptides act as hormones, or they may stimulate the body to release certain of its own endogenous hormones. Other peptides may promote tissue repair and stimulate collagen production, reduce body fat and stimulate lean muscle development, help regulate circadian rhythms to improve sleep, reduce inflammation and improve the immune system. Some peptides have been found to possess antibacterial, antiviral and antimicrobial properties while others have even demonstrated neuro-protective and neuro-regenerative properties.
In recent years, peptides have received increased interest in pharmaceutical, food, cosmetics and other fields. The high potency, specificity and good safety profile are the main strengths of peptides as new and promising therapies that may fill the gap between small molecules and protein drugs. Peptides possess favorable tissue penetration and the capability to engage in specific interactions with endogenous receptors. These positive attributes of peptides have driven research in evaluating peptides as versatile tools for drug discovery and delivery. With the ability to address immune function, improve inflammatory responses and neurological functions, peptides appear to hold great promise for treating diseases once thought to be untreatable.