Hi SDN!
Here's me question:
If an enzyme binds to PABA and another substrate to fully create its intermediate complex (EAB complex as opposed to ES because it has two substrates) and is exposed to its synthetic analog sulfanilamide, what kind of inhibition would it express?
The answer is that it would express noncompetitive/uncompetitive inhibition because the inhibitor is a competitive inhibitor to the enzyme, and acts as an allosteric inhibitor to the second substrate (even though it binds to the active site)
However, in my rationale, I was thinking that it would be competitive inhibition. Here is my though process
1. sulfanilamide (inhibitor) binds to the active site and that regardless of whether the uninhibited substrate (the one that is not PABA) is bound or not
2. the binding of sulfanilamide would halt the reaction from proceeding regardless of whether the enzyme was free or bound to the non-PABA substrate
3. because the inhibition is dependent solely on whether PABA or sulfanilamide reaches the enzyme or enzyme-substrate (substrate that is not PABA of course) complex, it should exhibit kinetics demonstrating competitive inhibition.
If anyone can explain this, I would be super grateful 😍😍
Here's me question:
If an enzyme binds to PABA and another substrate to fully create its intermediate complex (EAB complex as opposed to ES because it has two substrates) and is exposed to its synthetic analog sulfanilamide, what kind of inhibition would it express?
The answer is that it would express noncompetitive/uncompetitive inhibition because the inhibitor is a competitive inhibitor to the enzyme, and acts as an allosteric inhibitor to the second substrate (even though it binds to the active site)
However, in my rationale, I was thinking that it would be competitive inhibition. Here is my though process
1. sulfanilamide (inhibitor) binds to the active site and that regardless of whether the uninhibited substrate (the one that is not PABA) is bound or not
2. the binding of sulfanilamide would halt the reaction from proceeding regardless of whether the enzyme was free or bound to the non-PABA substrate
3. because the inhibition is dependent solely on whether PABA or sulfanilamide reaches the enzyme or enzyme-substrate (substrate that is not PABA of course) complex, it should exhibit kinetics demonstrating competitive inhibition.
If anyone can explain this, I would be super grateful 😍😍
