Enzymes as drug targets

Question 1

Spontaneous

Answer 1

ΔG°<0
System moves towards the equilibrium

Question 2

Non-spontaneous

Answer 2

ΔG°>0
* There is no driving force
* NO CHANGE over time

Question 3

ΔG‡

Answer 3

Free energy of activation

E.g. Zn, Cu, Fe

Question 4

Inorganic cofactors

Answer 4

Also known as metal cofactors. A substance that is required for the activity of an enzyme alongside the substrate.
E.g. Zn, Cu, Fe

Question 5

Haloenzyme

Answer 5

The protein part of the enzyme with the cofactor bound. [ACTIVE]

Question 6

Apoenzyme

Answer 6

The protein part of the enzyme minus its cofactor. [INACTIVE]

Question 7

Productive collision

Answer 7

When a substrate collides into an enzyme with the correct angle and amount of energy required

Question 8

Kcat

Answer 8

The turnover rate of substrates at a singular active site pet unit of time.

Measured: Vmax / [E]

High kcat -> fast turnover rate

Question 9

Catalytic efficiency

Answer 9

Kcat/Km

Question 10

Km

Answer 10

The concetration of substrate required to reach half of an enzymes Vmax.

A low Km also means ‘tight binding’ between substrate and enzyme.

The lower the Km the more efficient it is.

Question 11

Irriversible inhibitor

Answer 11

Enzyme inhibitor that covalently bonds to the active site of the enzyme.

Question 12

Reversible inhibition

Answer 12

Enzyme inhibitors that interact non-covalently with the enzyme

Question 13

Competitive inhibition

Answer 13

• Substrate and molecule compete for active site.
• Changes km

Question 14

Non-competitive inhibition

Answer 14

• The molecule binds elsewhere on the enzyme (allosteric site).
• Changes Vmax

Question 15

Peptidomimetic advantages

Answer 15

• Increased bioavailability (orally active)
• Increased stability
• Reduced antigenicity
• Reduced manufacturing costs