Human Function 9 - clotting II

Question 0

How do we get gla domains on factors?

Answer 0

Gla is a glutamate with an extra COO-, so we carboxylate a glu with a Vit K H2 dependent carboxylase(Vit K must first be reduced), and needs an HCO3-

Question 1

Which factors contain gla domains?

Answer 1

2 (prothrombin), 7, 9, 10

Question 2

Problems with bile production associated with cystic fibrosis also affects blood clotting in what way?

Answer 2

Bile is needed for vitamin K absorption
No vitamin K means no gla
No gla means factors 2,7,9,10 can’t work as well, and won’t be able to clot blood as easily

Question 3

Gla residues give the associated factors a high affinity to what ion?

Answer 3

Ca2+

Question 4

Role of Ca2+ in activating factors with gla domains

Answer 4

Calcium binds both negative phospholipids on membrane and negative gla to connect factors with platelet membranes

Question 5

Why do we need inter chain disulfide bonds in gla associated factors?

Answer 5

Factors get cut more than once

Question 6

What part of gla associated factors will eventually be degraded?

Answer 6

Part with gla (near N terminal end)

Question 7

By what mechanism do Coumadin and dicoumarol work?

Answer 7

They are both Vitamin KO analogs, so they are competitive inhibitors for vitamin KO reductases that convert Vit K H2 to Vit KO