Holoenzymes and Prosthetic Groups

[Strag]

Are these different terms for the same thing?

Enzymes + cofactors=holoenzymes/prosthetic groups

---

Members don't see this ad.

 

[dentalWorks]

Some enzymes need to first become "activated" in order for them to work. These special enzymes are called Holoenzymes

You activate enzymes by attaching a Cofactor on to them. There are 2 types of cofactors:
1) coenzymes = these are loosely attached to the enzyme
2) prosthetic groups = these are tightly attached (ionic or covalently) to the enzyme

 

[Strag]

So holoenzymes can be enzymes + coenzymes/prosthetic groups?

 

[dentalWorks]

So holoenzymes can be enzymes + coenzymes/prosthetic groups?

not "can be"... but "are"

Haloenzymes are enzymes + coenzyme/prosthetic group

 

[RCT PC CRN]

Enzymes which required cofactors to be functional are called apoenzyme when they are not functional and when they are functional (i.e attached to cofactors) called Holoenzyme (i.e the whole complex)

 

[Ibracadabra]

One example I can recall right out of my head is the RNA Polymerase in E.coli. It has a holoenzyme which includes the sigma factor, and when transcription initiates, the sigma factor falls off and the core enzyme works along to synthesize RNA.