The differences between peptides and peptide chains are:

  1. Different properties.

  2. Different characteristics.

  3. Different number of amino acids

First of all, the essential difference between peptides and peptide chains lies in their composition and properties. Peptides are compounds formed by α-amino acids connected by peptide bonds. They are the product of the protein decomposition process. Peptide chains are more specific. Two amino acids are connected to form a peptide bond. Multiple peptide bonds are connected to form a peptide chain. When a peptide chain is formed, water molecules are released. The number of peptide bonds in the peptide chain determines the number of water molecules released.

   Peptides have a wide range of solubility, but problems are prone to occur when forming secondary structures, especially in peptide chains containing multiple hydrophobic residues. Each time a peptide bond is formed, the peptide chain will release a water molecule, so the number of peptide bonds in the peptide chain directly affects the number of water molecules released.

Peptides usually contain 10 to 100 amino acid molecules, which can be simple dipeptides or tripeptides, or more complex peptides. In the application field of peptides, scientists have screened out mimetic peptides of various growth factors such as human erythropoietin, human thrombopoietin, human growth hormone, human nerve growth factor and interleukin. Although these mimetic peptides are different from the amino acid sequences of real cytokines, they still have biological activity and small molecular weight, which makes them more practical.