Lecture 5 - Protein Strucutre Flashcards Preview

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Flashcards in Lecture 5 - Protein Strucutre Deck (29):
1

Are structural proteins usually drug targets?

No

2

Which structural protein has been useful in drug design?

Tubulin

3

What are the three main drug target proteins?

Receptors, enzymes and transporters

4

What do transport proteins do (3)?

-Transport chemical building blocks (polar) across the cell membrane
-Transport neurotransmitters back into the neuron

5

What can go wrong with receptors?

-Over-activation of the cell due to too much messenger
-Under-activation of the cell due to tell little messenger

6

How do we fix over-activation and under-activation?

-Introduce antagonists
-Introduce agonists

7

What are the three families of receptors?

Ion channels
G-protein coupled
Kinase-linked

8

What is signal-transduction

The chain of events that involve secondary messengers, proteins and enzymes

9

What is the difference between the 3 types of protein drug targets?

1) Enzymes - there is a chemical transformation of the LMW compound
2) Receptors - there is a message and the LMW compound leaves unchanged
3) The LMW is moved into the cell unchanged after binding

10

What do all amino acids have? (4)

Carboxylic acid groups (Co2H)
Amino group (NH2)
Functional group (R)
Central C-H motif

11

What is special about the structure of proline

The side chain is bonded to both the amino and carboxylate groups

12

Where is proline normally found in the protein?

protein 'bends'

13

Why is proline also termed an imino acid

It has a 2° amino group instead of a 1° amino group

14

What are the two S-containing amino acids

Cysteine (SH)
Methionine (S-CH3)

15

Do charged amino acid residues stabilise protein conformations?

Yes

16

What are two non-standard amino acids?

Selenocysteine and pyrrolysine

17

What is a peptide bond

CO-NH with water spat out

18

Is the carbonyl atom usually cis or trans to the amino acid H atom

trans

19

Does the amide bond undergo rotation?

No it has some double bond character

20

What is primary protein structure?

The order in which amino acids are linked together

21

What is secondary protein structure?

Ordered regions within the protein, from specific hydrogen-bonding patterns

22

What is the tertiary protein structure?

The spatial arrangements of all atoms (including side chains and formation of disulfide bonds)

23

What is quaternary protein structure

The arrangement of two or more subunits

24

What are some examples of secondary structure

alpha helix, parallel beta sheet, anti-parallel beta sheet

25

Parallel beta sheets have what two groups on the same side?

Amino group

26

What is a key contributor to tertiary structure?

Van der waals

27

What amino acid residues will be located at the surface of proteins?

Polar

28

What is the result of the polar amino acid residues located at the surface?

They are less able to participate in the maintenance of the tertiary structure

29

What are the two similarities between enzymes, receptors and transporters?

1. All are protein-based biomolecules
2. They have recognition-based interactions with LMW compounds