Ligand binding lectures.
LIGAND BINDING LECTURE 1.
Life is the property/quality that distinguishes living organisms from dead organisms and
inanimate matter, manifested in functions like growth, metabolism, reproduction, and
response to stimuli or adaptation to the environment.
Ligand binding:
Metabolism sum of chemical reactions in a living organism. ENZYMES + CONTROL.
Growth an increase in the dry weight of an organism through cell division and
enlargement. ENZYMES + TRANSPORTERS + CONTROL.
Reproduction production of new or similar individuals from parent organisms. DNA +
CONTROL.
Response to stimuli or adaptation to the environment originating from within the organism.
RECEPTORS + CONTROL.
Control refers to turning on or off specific genes, cellular pathways or the function of
enzymes, transporters, and receptors.
Life is achieved through things interacting with other things.
So what are we?
LIFE is a contained series of controlled chemical reactions in an aqueous
environment, that results in metabolism, growth, reproduction, and a response to
stimuli.
A receptor is a protein that binds a neurotransmitter/modulator.
Non-covalent forces: Hydrogen bonds, Van der Waals, ionic bonds, hydrophobic
interactions.
, How do we characterise a system?
- Kinetics – the rate at which something appears or disappears
- Their affinities – strength of interaction e.g. between a protein and a ligand.
The association constant is used as the protein and ligand associate together, K A
The dissociation constant is used when they dissociate with each other. It is the inverse of
the association constant, KD
The kinetics of binding are related to the KD.
More on the dissociation constant…
The KD is a dimensionless number but is usually discussed as if it has molar units of
concentration
Biologically important non-covalent interactions have dissociation constants that
range from picomolar to nanomolar for strong interactions, to millimolar for the
weakest one.
The corresponding free energy change for the same reaction is usually taken for the
complex association version, with units of kJ/mol. Hence, large negative values
indicate tight interactions.
LIGAND BINDING LECTURE 1.
Life is the property/quality that distinguishes living organisms from dead organisms and
inanimate matter, manifested in functions like growth, metabolism, reproduction, and
response to stimuli or adaptation to the environment.
Ligand binding:
Metabolism sum of chemical reactions in a living organism. ENZYMES + CONTROL.
Growth an increase in the dry weight of an organism through cell division and
enlargement. ENZYMES + TRANSPORTERS + CONTROL.
Reproduction production of new or similar individuals from parent organisms. DNA +
CONTROL.
Response to stimuli or adaptation to the environment originating from within the organism.
RECEPTORS + CONTROL.
Control refers to turning on or off specific genes, cellular pathways or the function of
enzymes, transporters, and receptors.
Life is achieved through things interacting with other things.
So what are we?
LIFE is a contained series of controlled chemical reactions in an aqueous
environment, that results in metabolism, growth, reproduction, and a response to
stimuli.
A receptor is a protein that binds a neurotransmitter/modulator.
Non-covalent forces: Hydrogen bonds, Van der Waals, ionic bonds, hydrophobic
interactions.
, How do we characterise a system?
- Kinetics – the rate at which something appears or disappears
- Their affinities – strength of interaction e.g. between a protein and a ligand.
The association constant is used as the protein and ligand associate together, K A
The dissociation constant is used when they dissociate with each other. It is the inverse of
the association constant, KD
The kinetics of binding are related to the KD.
More on the dissociation constant…
The KD is a dimensionless number but is usually discussed as if it has molar units of
concentration
Biologically important non-covalent interactions have dissociation constants that
range from picomolar to nanomolar for strong interactions, to millimolar for the
weakest one.
The corresponding free energy change for the same reaction is usually taken for the
complex association version, with units of kJ/mol. Hence, large negative values
indicate tight interactions.
