Chapter 26.17, Problem 25P

Interpretation Introduction

Interpretation:

The pattern of the methyl group orientation in the $\text{β}$ sheet composed of only alanine residues is to be determined.

Concept Introduction:

A $\text{β}$ sheet is a secondary structural unit of peptides and proteins. It is composed of the hydrogen bonded polypeptide molecules; the hydrogen bonded through the $\text{N}-\text{H}$ group from one chain and $\text{C}=\text{O}$ group from another chain.

The geometry of the peptide bond is planar, with the two alpha carbons in anti conformation.