Bonds involved in Protein Structure
(Bonds Stabilizing the Primary, Secondary, Tertiary and Quaternary Structure of Proteins)
Proteins are the polymers of amino acids. Amino acids are joined together by a special type of covalent bond (peptide bond) to form linear structures called polypeptides. The polypeptides are then folded into specific structures to form the functional conformation of the protein. The folding of proteins into specific shapes and conformations are assisted and stabilized by many types of bonds in them. Some of these bonds are strong bonds whereas others are weak interactions. Important types of bonds involved in protein structure and conformation are Peptide bonds, Ionic bonds, Disulfide bonds, Hydrogen bonds and Hydrophobic Interactions. The current post describes the importance of each of these bonds and their role in the functional conformation of the protein.
What are the different types of bonds present in a protein?
Ø Typically, proteins possess the following FIVE types of bonds.
(1). Peptide bond
(2). Ionic bond
(3). Disulfide bond
(4). Hydrogen bond
(5). Hydrophobic Interactions
(1). Peptide Bond
Ø Peptide bond definition: a covalent bond formed between the carboxylic group of one amino acid and the amino group of another amino acid.
Ø Peptide bond is a strong covalent bond with high bond dissociation energy.
Ø It is formed by the joining of two amino acid residues during protein synthesis.
Ø The carboxylic group (- COOH) of one amino acid combine with the amino group (-NH2) of another amino acid to form the peptide bond.