COLLAGEN

Question 1

Primary structure of collagen

Answer 1

Repeated sequence: (Gly-X-Y)n

X,Y: mostly Pro and HyPro

Question 2

Secondary structure of collagen

Answer 2

left handed helical strycture of 1 poly peptide

Question 3

Procollagen + stabalizing forces

Answer 3

A right handed triple helix with globular parts at the ends so cant polymeize

from 3 left handed collagen helix
1. Interchain H- bonds
between peptide groups
2. Cross links between 2 Lys ( no Cys)

Question 4

Function of

globular parts :

Answer 4

1. Promote folding

2. Inhibit premature fiber formation

Question 5

Tropocollagen:

the globular parts at the ends are cut

Answer 5

the globular parts at the ends are cut by Procollagene peptidases

Question 6

Abnormalities of collagen formation

Answer 6

Inherited diseases:

Osteogenesis Imperfecta (fragile bones)
Procollagen (triple helix) formation is incomplete

Ehler-Danlos syndrome (strechable skin, hypermobyl joints)
Decreased activity of procollagen peptidase

Aquired disease:

Menkes syndrome (kinky hair, growth retardation):
A dietary deficiency of copper ion
needed for lysyl oxidase (lys-lys covalent cross link formation)