Pharmacodynamics : Molecular Binding Flashcards
List the four main protein targets for drug binding.
Receptors
Enzymes
Carrier proteins
Ion channels
There are three types of ion channels . What are they?
Ligand gated ion channels
Voltage gated on channels
Second messenger regulated channels
Example of a ligand gated ion channel
Nicotionic acetylcholine receptor
Examples of voltage gated ions channels
Selective sodium or calcium channels
Enzymes may act in three ways. What are they?
Enzyme substrate
False substrates
Prodrugs
There are two subgroups of enzymes that act as enzyme substrates. What are they?
Reversible and irreversible inhibitors.
Captopril and angiotensin converting enzymes are what type of enzyme substrate ?
Reversible
Two examples of enzyme substrate receptors that are irreversible are?
Aspirin and cyclo-oxygenases
Examples of drugs that act as false substrates are?
Anti cancer drug
What are carrier molecules?
These facilitate the transportation of polar organic molecules and ions across the cell membrane.
Example of a carrier molecule in the body
Carrier proteins that transport ions and organic acids from the renal tubule.
What is a symport channel?
Molecule and ion moving in the same direction
What are antiport channels?
Molecule and in moving in opposite directions
There are four types of receptors in the body
Ligand gated ion channels
G protein coupled receptors
Kinase liked and related receptors
Nuclear receptors.
What is another name for ligand gated ion channels?
Ionotropic receptors
How does dihydropyridine vasodilator drugs work?
Inhibits the opening of the L type calcium channels
How does benzodiazepine tranquillisers work?
By binding a region of the GABA receptor implied to increase the conductance of chloride ions across neuronal membranes during the membrane potential moves the membrane potential faster away from its threshold.
What is the action of sulfonyureas?
Used in the treatment Of diabetes which acts on ATP sensitive potassium channels of pancreatic Beta cells and therefore enhance insulin secretion.
Drugs may target enzymes as ……?
Inhibitors
False substrate
Pro drug
Drugs as enzyme inhibitors
The drug molecule is a substrate analogue that acts as a competitive inhibitor of the enzyme.
Example of a drug that acts a competive inhibitors of enzymes
Captopril, acts on the angiotensin converting enzymes
Can binding of a drug targeted on enzymes be irreversible. And if so what is an example?
Aspirin acting on cyclo-oxygenase.
Drugs may also act as false substrates
Where the drug molecule undergoes chemical transformation to form an abnormal product that subverts the normal metabolic pathway e.g fluorouracil acid replaces uracil as an intermediate in purine biosynthesis but cannot be converted into thymidylate, this blocks DNA synthesis and preventing cell division
What are receptors in a pharmacological context?
To a PROTEIN molecule which recognizes and respond to an endogenous chemical signal.
Some drugs can target enzymes and require enzymatic degeneration to convert them from an inactive form to an active form are called
Prodrugs
noradrenaline is a carrier protein that can be inhibited ot have a false substrate . What are they?
Tricyclic antidepressant. …… False substrate 39
Cocaine
Amphetamine And methyldopa are example of false substrates