Chapter 21, Problem 12A

Interpretation Introduction

Interpretation:

The relation between the secondary structure of a protein and its function needs to be explained with examples.

Answer to Problem 12A

Secondary structure of proten includes beta sheet structure and α-helix.

Explanation of Solution

Secondary structure of protein can form intermediate required for protein folding which ultimately leads to three dimensional tertiary structures. As secondary structure of protein includes the backbone of protein with dihedral angle so different proteins with different secondary structure can interact differently with bioactive molecules like hormones, enzymes, receptors etc. Thus function of protein depends on the secondary structure.

For example amino acids like proline and glycine are well known as helix breaker. These amino acids can disrupt the regularity of helical conformation. Amino acids like alanine, methionine and leucine prefer to adopt helical conformation. Amino acids with aromatic residues like phenyl alanine, tyrosine and tryptophan prefer to be in beta sheet structure as the ‘Pi’ electron clouds of the aromatic ring gets stability by ‘Pi-Pi’ stacking.