1.2cii - Ligand Binding Changes the Conformation of a Protein Flashcards
A ligand is…
a substance that can bind to a protein
R groups not involved in protein folding can…
allow binding to ligands
Binding sites will have complementary…
shape and chemistry to the ligand
As the ligand binds to a protein-binding site…
the conformation of the protein changes
The change in conformation of proteins causes a…
functional change in the protein
Allosteric interactions occur between…
spatially distinct sites
The binding of a substrate molecule to one active site of an allosteric enzyme increases…
the affinity of the other active sites for binding of subsequent substrate molecules
The activity of allosteric enzymes can vary greatly with small changes in…
substrate concentration, which is of biological importance
Many allosteric proteins consist of…
multiple subunits (have quaternary structure)
Allosteric proteins with multiple subunits show co-operativity in binding, in which…
changes in binding at one subunit alter the affinity of the remaining subunits
Allosteric enzymes contain…
a second type of site, called an allosteric site
Modulators regulate the…
activity of the enzyme when they bind to the allosteric site
Following the binding of a modulator…
the conformation of the enzyme changes and this alters the affinity of the active site for the substrate
Positive modulators…
increase the enzyme’s affinity for the substance
Negative modulators…
reduce the enzyme’s affinity for the substance
