Biology Reference
In-Depth Information
CHAPTER 5
THE AND ANGLES OF PROTEINS
INTRODUCTION
Most proteins are liner polymers of 20 different amino acid residues, e.g.
myoglobin discussed in Chapter 2. Hemoglobin consists of four chains, two
and two which are held together by hydrophobic interactions. Other
proteins, e.g. antibodies discussed in Chapter 1, have these linear polymers
connected by covalent bonds.
The amino acid residues are joined together by peptide bonds usually in the
trans-configuration (Fig. 5-1). Due to the de-localization of electrons, that
bond is considered as “partially” double. As a result, locally the peptide
bond is more or less flat, i.e. the two neighboring
N, H, C and O atoms
shown in Fig. 5-1 all lie in one plane.
Figure 5-1
. The peptide bond.
