BCMB20002 Lecture 4: Summary Notes

• School: University of Melbourne
• Department: Biochemistry and Molecular Biology
• Course: BCMB20002
• Professor: Terry Mulhern

Document Summary

All figures from lecture 3 and lecture 4 slides of p. gooley, melbourne university (unless stated otherwise) Length of peptide bond is 1. 32 (single bond = 1. 49 and double bond = 1. 27 ) We just draw it like this, but really is in 3d shape. Hence it has a double bond character. Our diagrams usually assume double bond characteristics. 4 planes, and each can swivel in respect to one another. The double bond character gives the peptide rigidity and planarity. 4 atoms define the angle (c (i-1), c (carbonyl), n (amine), c (i)) Trans two alpha carbons are on opposite sides. Although both isomers of proline are unfavourable (since there are alpha-alpha torsion, or alpha-delta torsion), the trans is more stable preceding the proline residue, especially in shorter chains. However, in longer polypeptides, the cis is taken more advantage of.