conversion from dA/dt to activity

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rangan
rangan's picture
conversion from dA/dt to activity

Sir/Madam:

I haven't done this in a while.
To convert rate of change of Absorbance (dA/min) to enzyme activity (moles [S] catalyzed/min):

Is dA/min(Rxn vol in mL / (e/1000)x1000?/sample vol in mL) -  correct? Since 'e' is always  some# .Mol -1. cm -1, and the result should be Moles of substrate (catalyzed)/minute.

1. Can you please confirm? or clarify?
2. Also, is any correction term needed in case of a coupled-enzyme assay?

Thanks.