Molecular Repair

Question 1

what proteins are involved in molecule repair?

Answer 1

a. Electrophiles
b. Most common damage is oxidation of sulfhydryl/thiol groups
i. Get changes in protein conformation
c. Thioredoxin
i. Sulfhydryl redox
ii. Re-reduce proteins that get oxidized
iii. Basically, you want all thigns to be in a reduced state–oxidation is usually a bad thing
iv. Use NADPH to reduce oxidized protein
d. Heatshock proteins (Hsps)
i. “protein police”–>refold denatured proteins
Highly conserved

Question 2

DNA repair

Answer 2

a. Direct repair
b. Photolyase
i. All animals but placental mammals have this enzyme
ii. Correct thymine dimers from UV radiation
iii. Uses blue light to separate the thymine dimer
c. Excision repair
i. Humans rely on this
ii. Epoxides bind covalently to DNA
iii. “bulky adduct” on DNA–>transcription is halted
iv. Nuclease snips the DNA the has the epoxide attached to it
1) DNA polymerase fills in the gap
2) Ligase seals

Question 3

lipid repair

Answer 3

a. Lipid peroxidation–damage to lipids

b. Vit E and C are needed to repair membrane lipds

Question 4

What is thioredoxin?

Answer 4

c. Thioredoxin
i. Sulfhydryl redox
ii. Re-reduce proteins that get oxidized
iii. Basically, you want all thigns to be in a reduced state–oxidation is usually a bad thing
iv. Use NADPH to reduce oxidized protein
d. Heatshock proteins (Hsps)
i. “protein police”–>refold denatured proteins
Highly conserved

Question 5

what are heat shock proteins?

Answer 5

i. “protein police”–>refold denatured proteins

Highly conserved