Article on hGH-Receptor

Question 1

What is the article looking at?

Answer 1

interactions between human growth hormone and its protein receptor on the membrane

Question 2

What are researchers trying to do?

Answer 2

get rid of individual amino acids in the primary sequences of growth hormones to determine which amino acids contribute to binding

change one amino acid on each growth hormone

Question 3

What doe researchers replace individual amino acids with?

Answer 3

Alanine

Question 4

Why use alanine and not glycine?

Answer 4

glycine can disrupt secondary structures due to its flexibility

Question 5

What does P2A mean in article?

Answer 5

proline changed to alanine at position 2

Question 6

What does T3A mean in article?

Answer 6

threonine to alanine at position 3

Question 7

Plot (Kd of mutant) versus (Kd of WT). What do different readings mean?

Answer 7

If plot is at 1, this means Kd of mutant = Kd of WT

If plot is above 1, this means weaker binding affinity when mutated than WT

If plot is below 1, this means greater binding affinity when mutated than WT

Question 8

What does plot (Kd of mutant) versus (Kd of WT) allow researchers to see?

Answer 8

which amino acids clearly help binding affinity of the growth hormone

the change in dissociation constant relative to wild type growth hormone

Question 9

Where are most of the amino acids that are important for binding located?

Answer 9

within the same region

this means that a section of the protein interacts with the receptor

Question 10

What does the helical wheel of the growth hormone show us?

Answer 10

there are hydrophobic and hydrophilic regions of the hormone

Question 11

Why did the researchers only mutate certain sections of the hormone?

Answer 11

they looked at homologous structures conserved in growth hormones

this allowed researchers to find which regions are highly conserved and important

then, they only tested these important regions

Question 12

Mab

Answer 12

Mab is a monoclonal antibody

Question 13

Why use Mab?

Answer 13

can see if Mab binds the same way with the same affinity to the mutant hormones as the WT

Mab binds to specific sites with specific affinities of the WT protein

Question 14

What happens if mutant hormones do not bind as well to Mab?

Answer 14

researchers know that they have accidentally changed the tertiary structure of the hormone