one unit of enzyme

[Thomas]

In article <53k3o9$ct0 at babe.lglobal.com>, jefff at lglobal.com (Jeff F) wrote:

> Hello!
> I am wondering if anyone can tell me the definition of one unit of
> enzyme!
> Thank you for your time!
> Jeff F
> jefff at lglobal.com
> Toronto

Unit is a former "unit" to describe the catalytic activity of an enzyme.
If you buy 1U of an enzyme you get an amount of enzyme that is able to
convert 1 mikromole of substrate per minute. The actual unit you should
use is Katal, which is a SI-unit and gives the same information in mole
per second, so:

1 U   = 1 mikromol/min
1 kat = 1 mol/s           (often given as pkat)

Conversion 1 U = 1.667*10-8 kat

Hope that answers your question
                                    Thomas

-- 

Sender:  Thomas Urbig
         Harvard University
         Institute for Molecular and Cellular Biology
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         Email:  Thomas at hastingslab.harvard.edu