Metals

Question 1

How is zinc secreted in fertilised oocytes?

Answer 1

last few hrs of maturation oocyte takes up millions of zinc
(cell cycle arrest at metaphase)

Fertilisation triggers zinc ejection
(resumption of meiotic cell cycle).

Question 2

How do Menkes and Wilson’s disease differ?

Answer 2

M - ATP7A mutated (transports Cu from SI to blood) - sparse Cu in brain

W - ATP7B mutated

Question 3

What is the cause of acrodermatitis enterpathica?

Answer 3

Mutated SLC39A4 (transmembrane protein serving as Zn uptake).

Question 4

what happens to zinc in oxidative stress?

Answer 4

Zn2+ released from proteins with a zn finger motif –> zn redistributed.

Function of proteins from which released and to which binds changes.

Zinc is a pro-oxidant.

Question 5

How many EF fingers does calmodulin contain?

Answer 5

4.

Question 6

what trend can be observed in ligand binding affinity and metal ions?

Answer 6

Going from L to R in the periodic table, binding gets stronger (fentimolar is ten to the minus 15)!

Question 7

What is the function of MT3?

Answer 7

Metallothionein, brain isoform, neuronal growth inhibitory activity.
There are seven zincs and 20 sulphurs (zinc normally coordinates with 4 sulphurs!)

Question 8

What kind pf copper is cupric and cuprous? How does this differ to zinc and iron?

Answer 8

Cu2+ and Cu+. Zinc is always 2+.
Fe2+ is ferrous
Fe3+ is ferric.