Bacterial Toxins

Question 1

Shiga

Answer 1

• RNA N-glycosidases
• cleavage by ricin A?
• leads to inactivation of protein synthesis and cell death

Question 2

Cholera

Answer 2

Increases adenylate cyclase activity, leading to increase in cAMP, leading to loss of cell nutrients and diarrhea.

• AB type protein toxins
• A: catalytic moiety (1)
• B: cell binding moiety (5)
• 1A and 5B polypeptides associate w/ each other by non covalent interactions
• leads to inc. secretion (diarrhea)

Question 3

Botulinum

Answer 3

Disrupts SNARE proteins and prevents binding of endosomes to cell membrane.

Question 4

Anthrax

Answer 4

• edema factor and adenylate cyclase toxin
• oligomer is formed and is endocytosed into cell
• acidification of endocyte causes conformational changes
• edema factor is adenylate cyclase enzyme
• anthrax lethal factor

Question 5

Tetanus

Answer 5

• spastic paraylsis- all muscle group involuntarily contract
• typically associated w/ traumatic injury
• interactions of tetanus toxin w/ motor neuron and an interacting spinal cord interneuron
• enters neurotransmitter in vessicle and travels up axon
• leads to involuntary muscle contraction

Question 6

Diptheria

Answer 6

Inactivates elongation factor 2, leading to inhibition of protein synthesis by the ribosome.