What are the 6 Major Chemical Bonds or Interactions In Proteins?

6 Major chemical bonds in Proteins

In this post let me  give you a quick summary of major bonds in Proteins.

Proteins are biomolecules  made up of amino acids joined by peptide bond.

Bonds in protein:

1. Peptide bond

• Peptide bond is formed when a water  molecule is eliminated during a reaction between 
• –NH2 (amino group) of one amino acid and –COOH (carboxyl group) of another.

Peptide bond or amide bond Characteristics

watch this video on peptide bond for more clarity of concept

• Covalent bond that joins 2 amino acids
• Dehydration synthesis: release of H2O
• Partial double bond character: as shorter than a single bond
• Rigid and planar: rotation around the bond is restricted
• Trans configuration: less steric hindrances of adjacent amino acid side chains
• Uncharged : only side chains and N and C terminals are charged.

2. Disulfide bonds: covalent bond formed between Sulphur containing amino acid

• It forms when the -SH groups of two cysteine residues are covalently linked as a dithiol by oxidation
• It may be formed between different chains of amino acids or between different parts of the chain.
• It provide some rigidity to the protein molecule.

3. Hydrophobic Bond 

• It is formed between two non polar groups or hydrophobic amino acids.

• Hydrophobic bonding forms an interior, hydrophobic protein core, where most hydrophobic side chains can closely associate and are shielded from interactions with solvent water.
• Most important driving force in protein folding

4. Hydrogen Bond

• A hydrogen bond is the electromagnetic attractive interaction between polar molecules, in which hydrogen is bound to a highly electronegative atom, such as nitrogen, oxygen or fluorine. It is a weak bond.
• Amino acids with side chain containing –OH, -NH2 etc participate in H-bonding

5. Ionic Bond 

• Ionic bond forms  due to attractive force between oppositely charged ionised groups. 

• Refer the above figure where aspartic acid is negatively charged and lysine is positively charged

• The Van der Waals force is a transient, weak electrical attraction of one atom for another. 
• It is the sum total of all non covalent associations between electrically neutral molecules.

Watch this video on bonds in proteins for better understanding. Thank you