ser/thr kinase II

Question 1

Protein kinases function to

Answer 1

situate the amino acid residue and ATP molecule in proper position for this reaction to occur.

Question 2

Phosphorylation of the protein

Answer 2

changes the protein’s activity.

Question 3

Most phosphorylation events function to:

Answer 3

activate inactive proteins, but phosphorylation may inactivate proteins as well.

Question 4

Types of protein modification include:

Answer 4

1. Protein phosphorylation
2. Acetylation
3. Glycosylation
4. Ubiquitinylation
5. Proteolytic cleavage

Question 5

Adenosine triphosphate (ATP) is a nucleotide made of:

Answer 5

ribose, a purine base (adenosine) and three phosphate groups.

Question 6

The phosphate bonds of ATP are :

Answer 6

energy rich and can phosphate groups can be donated to other molecules.

Question 7

Protein kinases can be classified based on the following:

Answer 7

1. residues that they phosphorylate
2. substrate they phosphorylate
3. the stimulus that activates them–this stimulus may be a receptor, secondary messenger or cyclin
4. their phylogenic relationship –kinases separated based on structural and functional similarities into “families”

Question 8

CAMK kinases are examples of naming based on

Answer 8

their phylogenic relationship –kinases separated based on structural and functional similarities into “families”

Question 9

insulin receptor, protein kinase a is stimulated by

Answer 9

secondary messenger cAMP

Question 10

CDK2 is stim by

Answer 10

cyclin

Question 11

Protein kinases consist of two lobes:

Answer 11

one large and one small.

Question 12

Between the lobes is a

Answer 12

cleft where the ATP and substrate bind.

Question 13

The substrate associates with the ____ lobe in the cleft.

Answer 13

large

Question 14

Protein kinases have highly conserved ______

Answer 14

catalytic cores with a glycine rich loop and an activation loop.

Question 15

The glycine rich loop plays a role in ______

Answer 15

altering the conformation of the enzyme.

Question 16

In the closed conformation, the glycine loop forces the ______.

Answer 16

ATP into the right position for the phosphorylation reaction

Question 17

In the open confirmation, the glycine loop changes its position to allow for the _______

Answer 17

exchange of GDP for GTP.

Question 18

In 70% of kinases, the activation loop must be ______ in order to activate the kinase.

Answer 18

phosphorylated

Question 19

The active conformation is _____

Answer 19

highly conserved.

Question 20

The active site is not a useful drug target because:

Answer 20

drug inhibitors would lack specificity

Question 21

Why are inactive sites good drug targets?

Answer 21

Inactive conformations have varying conformations and can be specifically inhibited.

Question 22

Inhibition of inactive site can be achieved by introducing a _____

Answer 22

“pseudo-substrate” that mimics the actual substrate but blocks kinase activity.