TBL2 Flashcards
_____(Tamiflu) is a potent and selective transition-state
inhibitor of the influenza virus A and B neuraminidase
Oseltamivir
Abzymes
Abzymes[catalytic antibodies] against cocaine esterase → ↑cocaine
degradation in the body → used in addicted individuals. Allopurinol, Penicillin
Cofactors
Metal ions, inorganic (e.g., zinc, iron, or copper) referred as cofactors
Also called metaloenzyme
coenzymes
-Organic compound (e.g., pyridoxal phosphate or flavin)
- Organometallic compound (e.g., heme or cobalamin)
if tightly bound (by covalent
bond) referred to as
prosthetic group
Coenzymes that only transiently associate with the enzyme are called
cosubstrates. Cosubstrates dissociate from the enzyme in an altered
state (NAD+] Coenzymes commonly derived from vitamins
Coenzymes that are prosthetic group examples
g., biotin,
heme, FAD flavin, and retinal
What’s enzymes are reduced by proton pump inhibitors
• Gastric proton pump inhibitors [H+/K/ATPase] → ↓HCL in stomach
→ ↑pH → ↓ efficiency of gastric enzymes pepsin, amylase, lipase
What is used to inhibit the production of methanol and ethylene glycol toxicity and what enzyme does it inhibit
Ethanol has ~20 times more affinity for alcohol
dehydrogenase [ADH] and competitively inhibits this enzyme. Km
values of ADH for ethanol. 1 & methanol. 20. Rx. Ethanol used to treat
methanol and ethylene glycol toxicity
Competitive inhibitors km and Vmax, examples of drugs
Km higher and vmax unchanged
Malonate inhibits succinate dehydrogenase
* Sulfonamide inhibits dihydropteroate synthase
* Methotrexate inhibits dihydrofolate reductase
* Captopril inhibits angiotensin-converting enzyme [ACE]
* Statins inhibit HMG coA reductase
* Ethanol inhibits alcohol dehydrogenase
Noncompetitive inhibition km and vmax and examples of medications
km: no change, vmax decreased, binds to enzyme alone
vmax decreases
* Acetazolamide [diuretic] acts as a noncompetitive inhibitor of carbonic anhydrase used in glaucoma and altitude sickness
* Allopurinol in high doses, a noncompetitive inhibitor of xanthine oxidase
uncompetitive inhibitor
km and vmax both decrease by same factor
lithium as an example
examples of irreversible inhibitors
Lead, Disulfiram,Penicillin,Omeprazole
Lansoprazole,5-Fluorouracil
lead poisoning
iIrreversible inhibitors
nhibits: alpha-aminolaevulinic acid (ALA) dehydratase and
ferro chelatase, enzymes involved in the biosynthesis of heme
Abdominal pain, sideroblastic
anemia, irritability, headaches, impaired
nervous system development, encephalopathy.
Treatment: Ca-EDTA with dimercaprol
drug for alcoholics
irreversible
disulfiram!
Aldehyde dehydrogenase has an active cysteine residue is irreversibly modified by disulfiram
makes accumulation of acetaldehyde in blood and tissues and leads to alcohol avoidance
penicillin
Irreversible, Transition state analog, it binds and forms covalent
bond with serine residue of transpeptidase →
irreversible inhibition of bacterial cell wall synthesis
Omeprazole
Lansoprazole
Irreversibly inhibits K+/H+ ATPase by either
covalently modify or tightly binds to active site
treats stomach ulcers
