Proline overview

Question 1

Proline

Answer 1

Pro or P

Question 2

Structure:

Answer 2

• Folds back onto the main chain of the amino acid
• Side chain is connected to the backbone at two places:
  the C(a) and the N.
• Therefore, it is not actually an amino acid, but an imino acid.

-Does not have a backbone proton, and thus is not good for helices
and strands (unless it is the N-terminal residue)

• Due to the extra covalent bond, proline is already pre-bent, and
  thus good for turns

-Even though it is very hydrophobic, it often sits at the surface

Question 3

Proline is an…

Answer 3

imino acid, not
an amino acid, and has a nitrogen
in the aliphatic ring system

Question 4

Proline (Pro, P) has a…

Answer 4

three carbon
side chain bonded to the alpha-amino
nitrogen.

-The heterocyclic pyrrolidine ring
restricts the geometry of polypeptides