Tertiary structure is the 3-D folding of a polypeptide chain, and quaternary structure is simply several chains folded into tertiary structure all tangled up together.

Then there is one final level of protein structure, and that is called quaternary structure. And quaternary structure describes the bonding between multiple polypeptides. The same interactions that determine …

The process of going from primary structure to tertiary or quaternary structure establishes a protein's final shape, chemical properties, and cellular functions.

Now, any protein that's made up of a single polypeptide is only going to have primary structure, secondary structure and tertiary structure, but if we're dealing with something like hemoglobin, that's …

The way these individual chains fit together into an overall three dimensional arrangement is called quaternary structure. Only multi-subunit proteins have quaternary structure.

Below we delve more into the interactions that stabilize the tertiary structure (overall fold) and quaternary structure (interactions between subunits) of proteins.

So as you can see, the conformational stability of a protein depends not only on all of these interactions that contribute to primary, secondary, tertiary, and quaternary structure, but also what sort of …

It exhibits quaternary structure with multiple polypeptide chains. A It exhibits quaternary structure with multiple polypeptide chains.

This disrupts the quaternary structure of proteins that consist of more than one subunit. The bands visualized under reducing conditions reflect the size of the individual subunits.

A new drug is developed which selectively cleaves covalent bonds between two sulfur atoms of non-adjacent amino acids in a polypeptide chain. Which level of protein structure in affected molecules …