Question

mention a protein having quaternary structure.also,name its poplypeptide chain

Answer 1

Protein having Quarternery Structure: hemoglobin

Polypeptide chain:
Hemoglobin has a quaternary structure characteristic of many multi-subunit globular proteins.[32] Most of the amino acids in hemoglobin form alpha helices, and these helices are connected by short non-helical segments. Hydrogen bonds stabilize the helical sections inside this protein, causing attractions within the molecule, which then causes each polypeptide chain to fold into a specific shape.[33] Hemoglobin's quaternary structure comes from its four subunits in roughly a tetrahedral arrangement.[32]

The four polypeptide chains are bound to each other by salt bridges, hydrogen bonds, and the hydrophobic effect.