Thursday, June 27, 2013

The Best Enzyme


Better Biochemistry
While I was collecting posts on biochemistry, I came across one that I wrote almost five years ago. It was about a new record for catalytic proficiency. As you know, enzymes speed up reactions that occur naturally and spontaneously. The difference between the spontaneous rate and the rate catalyzed by an enzyme is called the catalytic proficiency.

That old post [Enzyme Efficiency: The Best Enzyme] had a nice graphic showing the spontaneous rates of some reactions that take place quickly inside a cell.

Here it is ....

And here's how the information in that 2008 post got incorporated into the latest edition of my textbook.


  1. I'm curious how superoxide dismutase ranks with respect to catalytic proficiency, since its rate constant is nearly 10^10/M/s if I recall. Does anyone know what the non-enzymatic rate constant is for the dismutase reaction?

  2. Not particularly meaningful given how potentially hugely inaccurate all these extrapolations to < 10^(-15) are.