Peptides are short chains of amino acids linked by peptide bonds. Typically, peptides contain 2-50 amino acids. Anything shorter than a peptide is an amino acid or dipeptide, while longer chains are called proteins.
Key features of peptides:
Short chains of amino acids
Typically have 2-50 amino acids
Linked together by peptide bonds
Longer chains are called proteins
Shorter chains are amino acids or dipeptides
Peptides play several crucial roles in the body:
Cell signaling - Peptides relay signals between cells and tissues to coordinate bodily functions. For example, insulin is a peptide hormone that regulates blood sugar levels.
Immune defense - Antimicrobial peptides defend against invading microbes.
Bioactive functions - Many peptides have biological activity and serve functions like blood pressure regulation or nerve transmission.
Additionally, peptides have some key advantages over larger protein therapeutics:
Higher activity
Better stability
Increased cell permeability
Lower antigenicity
Easier to synthesize
This makes peptides very promising as pharmaceutical agents. There are already several FDA-approved peptide drugs on the market, with thousands more in development. Some examples of therapeutic peptides include:
Liraglutide for diabetes
Leuprolide for prostate cancer
Copaxone for multiple sclerosis
In summary, peptides are short chains of amino acids that play crucial signaling, defensive, and bioactive roles in the body. Their small size gives peptides drug-like properties, making them promising as pharmaceutical agents to treat various diseases. Research into therapeutic peptides is rapidly expanding as scientists uncover the many functional roles these molecules play.