What factors contribute to tertiary structure stability Give

What factors contribute to tertiary structure stability? Give specific examples of the bonds involved, and which one is most important.

Solution

Primary structure of protein means linear sequences of amino acids and second structure constitute helical conformation with hydrogen bonding (parallel and anti parallel) where as tertiary structure is means that third type found in protein is called tertiary protein structure.

Tertiary structure : it is a compact structure with hydrophobic side chains held interior while hydrophilic groups are on the surface of the protein molecule. This type of arrangement ensures stability of molecules.

It determine by variety of bonding interaction between the side chains on the amino acids.   These type of interaction stronger than hydrogen bonding as result in a number of folds, bends, and loops in the protein chain.

Tertiary structure has 4 types of bonding:

1. Disulfide bonding

2. Hydrogen bonding

3. Salt bridges

4. Non-polar hydrophobic interactions

Note: Hydrophobic interaction contribute stability to the tertiary structure of proteins.

1. Disulfide bond: it is formed by oxidation of the sulfhydryl groups on cysteine eg: insulin protein

2. Hydrogen bond: It is occur between side chains eg: prion protein , tyr 128 is hydrogen bond to asp 178

3.Salt bridge: it result in neutralization of an acid and amine on side chain eg: salt bridge glutamic acid and lysine

4. Hydrophobic interactions: it is very significant for the stability of tertiary structure