PNP , production

PNP production was monitored at 402 nm and quantitated using extinction coefficients determined experimentally for each reaction medium. The fraction of reactant conversion to product was given by the ratio (Aj. - Aq)/(A - A ) where the subscripts t, o, and <<> refer, respectively, to absorbance values taken at time t, initially, and at long reaction times when PNP liberation clearly stopped. 

Kinetic assays are usually performed spectrophotometrically using PNP-pdT as a substrate. The initial product PNP-phosphate (+ dT) is converted to PNP in an alkaline phosphatase-coupled reaction. The rate of PNP production is monitored at 405 nm, where 8405 is 1.83 x 10 M cm ... 

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