Allosteric enzymes
2 subunits that convert between T and R state
What does binding at the first binding site do to allosteric?
causes a conformational change, makes it go to R state
How does effectors influence allostery?
Allosteric inhibitors stabilize the T state
Allosteric activators stabilize the R state
What does ATCase do?
combines aspartate and carbamoyl phosphate to make a multisubunit enzyme complex
What is the allosteric inhibitor and activator for ATCase?
Inhibitor: CTP
Activator: ATP
What are the types of subunits?
There are 2 groups of trimers (catalyic) and 3 groups of dimers (reglatory)
In total 12
Does ATCase obey Michaelis-Menten kinetics?
NO, sigmoidal binding curve instead of a hyberbolic
What is the conformational change that happens when T state goes to R state?
R state opens up in the middle, allows for rotation in the middle
Proteins are modified by phosphate groups at which residues?
Ser, Thy, Tyr
What does glycogen phosphorylase do?
cleaves a glycolic bond and substitutes a phosphate group when it leaves
What are the two forms of glycogen phosphorylase?
A: phosphorylated at Ser14
B: unphosphorylated
What state does phosphorylate promote?
R form, active form, causes conformational change
What does PFK do?
Turn F6P and ATP to FBP and ADP
What is the inhibitors and activators of PFK?
Inhibitors: ATP,
Activators ADP, AMP, and F2,6P
Why is ATP a inhibitor and a substrate?
ATP favors the T state at the regulatory site (has no preference in the substrate site)
What amino side chains favor which state of PFK?
Arg likes R state
Glu likes T state
