4

Question 1

how is hemogolbin described

Answer 1

tetramer or dimer of alpha-beta protomers

Question 2

what feature makes a structure an oligomer

Answer 2

repeating units

Question 3

what is the repeating unit in an oligomer

Answer 3

protomer

Question 4

what are oligomers associated with

Answer 4

a symmetry form

Question 5

how are errors in translations affected by the quaternary structure

Answer 5

less critical

Question 6

what is pseudosymmetry

Answer 6

non-identical homologous subunits are related by symmetry

Question 7

what are the types of symmetry

Answer 7

Cyclic, dihdedral, tetrahedral, octahederal, isocaheadral

Question 8

describe the axes in Dn

Answer 8

2N protomers arranged around 2 axes
one N fold and one 2 fold

Question 9

what is helical symmetry

Answer 9

protomers related by rotation and translation

Question 10

what are the fold axes in tetrahedral symmetry

Answer 10

3 fold and 2 fold

Question 11

what are the fold axes in octahedreal symmetry

Answer 11

2, 3, 4

Question 12

what are the fold axes in icosahedral

Answer 12

2, 3, 5

Question 13

what are the types of forces in protein folding

Answer 13

weak, non covalent

Question 14

what can destroy the native state of a protein (4)

Answer 14

heat pH detergents organic solvents

Question 15

what are the two denaturants of interest

Answer 15

guanidinium and urea

Question 16

descibe the effects of the two denaturants of interest

Answer 16

chaotropic, water soluble, disrupt H-bonding

Question 17

what are the two reducing agents of interest

Answer 17

beta-mercaptoethanol and DTT (dithiothreitol)

Question 18

what kind of process is denaturation

Answer 18

cooperative

Question 19

what is the midpoint of transition for denaturant characteristic of

Answer 19

protein and denaturant

Question 20

what effect does unfolding part of the protein have on the energy required to unfold the rest of the structure

Answer 20

decreases

Question 21

what is the state between secondary and tertiary structure

Answer 21

molten globule

Question 22

what is misfolding

Answer 22

stable structure but not native

Question 23

what are the disease states leading to misfolding

Answer 23

amyloidosis - huntington’s / alzeimers
prion disease - BSE, scrapie
collagen defects - osteogenesis imperfecta

Question 24

what 2 things can assist with folding

Answer 24

chaperones or isomerases

Question 25

what are the 2 types of molecular chaperones

Answer 25

chaperonins and Hsp

Question 26

what sre the two types of isomerases

Answer 26

protein disulphide isomerase
peptide prolyl isomerase

Question 27

how do chaperones work

Answer 27

isolate misfolded proteins so they do not interadr

Question 28

what do chaperones use to carry out their activity and why

Answer 28

energy (ATP hydrolysis) to unfold the protein substrate

Question 29

is chaperone activity kinetic or thermodynamic

Answer 29

kinetic

Question 30

what are the two bacterial chaperones of interest

Answer 30

DnaK Hsp70 and DnaJ Hsp40

Question 31

what is responsible for the nucleotide exchange associated with protein assisted folding

Answer 31

GrpE

Question 32

what does ATP hydrolysis do for assisted folding

Answer 32

changes binding site for protein substrate

Question 33

describe Hsp 70 and Hsp 40 actions

Answer 33

DnaK binds with ATP then associates with DnaJ and midfolded substrate

Question 34

what is the GroEL/GroES complex (chaperonin)

Answer 34

1. GroES cap binds to GroEL ring
2. unfolding of misfolded protein with ATP hydrolysis (7 ATP)
3. another misfolded substrate enters with 7 ATP
4. release of GroES cap, ADP and protein

Question 35

what are the two properties of PDI

Answer 35

isomerase or oxidoreducatase