Determining composition and sequence of proteins

Question 1

What are reducing agents for for disulfide bridges?

Answer 1

1. B-mercaptoethanol (BME)

2. Dithiothreitol (DTT)

Question 2

What are two ways to break large proteins into “workable,” smaller peptides?

Answer 2

1. Enzymatic cleavage

2. chemical cleavage

Question 3

What is enzymatic cleavage?

Answer 3

1. breaking amino(before)/carboxyl(after) peptide bond relative to recognized side chain

Question 4

What are the four enzymatic cleavage enzymes?

Answer 4

1. Trypsin
2. chymotrypsin
3. Staph. aureus protease
4. Thermolysin

Question 5

Trypsin

Answer 5

1. cleaves carboxyl group whenever it recognizes an R or K

2. Basic AA

Question 6

chymotrypsin (aromatic smells, WYF smells)

Answer 6

1. carboxyl whenever it recognizes W, Y, or F

2. Aromatic AA

Question 7

Staph. aureus protease

Answer 7

1. carboxyl whenever it recognizes D or E

2. Acidic AA

Question 8

Thermolysin

Answer 8

1. amino whenever it recognizes F, I, L, or V

Question 9

chemical cleavage: cyanogen bromide

Answer 9

carboxyl for m