CMB Exam 1 - Drugs/Toxins

Question 1

doxorubicin

Answer 1

human type II topoisomerase inhibitor; chemotherapeutic

Question 2

pertussis toxin

Answer 2

(bordetella pertussis) ADP-ribosylates the Gi subunit locking it in inactive conformation, resulting in increased cAMP and loss of cilia in the respiratory track. Cannot move mucus = whooping cough.

Question 3

warfarin (Coumadin)

Answer 3

Used for treatment and prevention of thromboembolic events. Narrow therapeutic window, 20% hospitalization rate for new patients.

Question 4

colcemid

Answer 4

Binds tubulin & inhibits microtubule polymerization, disrupting mitosis in metaphase. Anti-cancer drug.

Question 5

Erythromycin

Answer 5

(PRO) Binds to the 50S subunit and inhibits translocation

Question 6

HNO2

Answer 6

deaminating agent: Convert adenine, guanine, and cytosine into hypoxanthine, xanthine, and uracil, respectively

Question 7

proflavin

Answer 7

intercalating agent: inserts between stacked DNA bases, resulting in frameshift mutations

Question 8

diphtheria toxin

Answer 8

Inhibits eEF-2 and prevents translocation

Question 9

MNNG

Answer 9

alkylating agent: attaches alkyl group to bases (adds CH3 to the O); converts guanine to O6-methylguanine

Question 10

albuterol

Answer 10

Relaxes smooth muscles, prevents premature labor

Question 11

lyso-phosphatidylcholine

Answer 11

Component of snake venom that disrupts membrane structure.

Question 12

Puromycin

Answer 12

(EUK and Pro) Resembles aminoacyl-tRNA and binds to A-site

Question 13

actinomycin D

Answer 13

Binds tightly to dsDNA (deoxyguanosine residues) and acts as an intercalating agent at G-C pairs. This will inhibit RNA synthesis. Not PRO or EU specific.

Question 14

Ricin

Answer 14

(EUK) Inactivates 60S subunit of ribosome

Question 15

Streptomycin

Answer 15

(PRO) Causes misreading of the genetic code.

Question 16

benzo[a]pyrene

Answer 16

carcinogen from cigarettes: oxidized within cells and then covalently binds to guanine, distorting helix

Question 17

Choramphenicol

Answer 17

(PRO) Inhibits peptidyl transferase activity on ribosomes

Question 18

Cycloheximide

Answer 18

(EUK) Inhibits peptidyl transferase activity of the 60S (Eukaryotes) ribosome, inhibiting translocation

Question 19

cholera toxin

Answer 19

(vibrio cholerae) toxin is endocytosed and ADP-ribosylates the Gs subunit (to inactivate its GTPase). Since it’s stuck in active mode, continuous cAMP production resulting in massive water loss through intestines.

Question 20

phallotoxin (phalloidin)

Answer 20

Binds tightly to AFs and prevents their dissociation into G actin. Prohibits dynamic behavior.

Question 21

ciprofloxacin

Answer 21

bacterial type II topoisomerase inhibitor; antimicrobial

Question 22

5-Fluorodeoxyuracil

Answer 22

Cancer drug - disrupts nucleotide synthesis

Question 23

etoposide

Answer 23

human type II topoisomerase inhibitor; chemotherapeutic

Question 24

colchicine

Answer 24

Binds tubulin & inhibits microtubule polymerization, disrupting mitosis in metaphase. Anti-cancer drug.

Question 25

methotrexate

Answer 25

Anti-cancer drug that blocks the folic acid binding site on DHFR, preventing cell division.

Question 26

Alpha-Amanitin

Answer 26

Mushroom poison - doesn't have effect on prokaryote RNA polymerase

Question 27

oxytosin

Answer 27

Contracts smooth muscle, induces labor

Question 28

Rifampicin

Answer 28

Specifically inhibits the initiation of transcription in Prokaryotes, mitochondrial polymerase

Question 29

ethidium bromide

Answer 29

intercalating agent: inserts between stacked DNA bases, resulting in frameshift mutations

Question 30

cytochalasin B & D

Answer 30

Fungal toxin that binds to the + end of actin filaments to block elongation. Causes break up of filaments and inhibits mitosis.

Question 31

Tetracycline

Answer 31

(PRO) Inhibits binding of aminoacyl-tRNA to A-site

Question 32

paclitaxel/taxol

Answer 32

Stabilizes microtubules to arrest mitosis. Anti-cancer drug.

Question 33

nocodazole

Answer 33

Binds tubulin & inhibits microtubule polymerization, disrupting mitosis in metaphase. Anti-cancer drug.

Question 34

nalidixic acid

Answer 34

bacterial type II topoisomerase inhibitor; antimicrobial

Question 35

vincristine

Answer 35

Binds to tubulin & selectively inhibits rapidly dividing cells. Anti-cancer drug.

Question 36

vinblastin

Answer 36

Binds to tubulin & selectively inhibits rapidly dividing cells. Anti-cancer drug.

Question 37

Allopurinol

Answer 37

A purine analog used to treat gout, acts as a competitive inhibitor of xanthine oxidase, causes patient to excrete (excess) uric acid