Lec 1-4

Question 1

What are the four primary drug targets in a body and what are some important exceptions?

Answer 1

• receptors
• ion channels
• enzymes
• carrier molecules
  (exceptions)
• cytokines (mAbs)
• DNA (antitumour and antimicrobial drugs- e.g. trastuzumab)

Question 2

What does affinity mean?

Answer 2

Affinity is the attraction of a ligand for a receptor.

Question 3

What does efficacy mean?

Answer 3

Efficacy is the the ability of a drug to produce an effect (intrinsic activity). Scale of 0-1: Maximum effect= 1, No effect= 0

Question 4

What are the properties of agonists?

Answer 4

Agonists have affinity and efficacy (mimics- mimicking endogenous compounds to generate cell response/signalling)

Question 5

What are the properties of antagonists?

Answer 5

Have affinity but no efficacy (prevents/ blocks endogenous compounds from bounding to reduce cell signalling)

Question 6

What are the 4 receptor families and their time scale?

Answer 6

ligand gated ion channels (ms), G-protein coupled receptors (s), kinase-linked receptors (hours), nuclear receptors (hours) - hours: due to gene transcription involved

Question 7

Describe the structure of LGIC and their three major properties.

Answer 7

LGICs are multi-subunit complex (5 TM2 helices with a sharp kink inwards forming the gate). They all have the properties of:

• activated in response to a specific ligand
• conduct ions through the otherwise impermeable cell membrane
• select among different ions

Question 8

What are the 2 types of medicines that target LGICs and give some example?

Answer 8

• GABAa: benzodiazepines and barbiturates (sedation and anxiolytic effects), flumazenil
• Glutamate: ketamine (aneasthetic)`