NURSING ANM AND GNM

Detailed explanation-1: -Protein quaternary structure is the fourth (and highest) classification level of protein structure. Protein quaternary structure refers to the structure of proteins which are themselves composed of two or more smaller protein chains (also referred to as subunits).

Detailed explanation-2: -Hence, insulin is a quaternary structure.

Detailed explanation-3: -Surrounding its core, the monomer has two extensive nonpolar surfaces. One of them is a flat one that is aromatic and gets buried when there is a dimer formation. The other surface is more extensive and disappears when a hexamer is formed. This is called the quaternary structure of insulin.

Detailed explanation-4: -QUATERNARY STRUCTURE Zinc ions cause insulin to form into a stable hexamer (6 A & B chains). This hexameric form is found in beta-cells of the islets of Langerhans, and it is seen as helpful in prolonging the usefulness of insulin in treating diabetes.

Detailed explanation-5: -Insulin is a small globular protein containing two chains, A (21 residues) and B (30 residues) (Fig. 2.1A). Stored in the cell as a Zn2+-stabilized hexamer, the hormone dissociates in the bloodstream to function as a Zn2+-free monomer (Fig. 2.1B).