Activity measurements in solution

Activity Measurements in Solution. The 2 -chloro, 4 -nitrophenyl / -D-glycosides offer an attractive alternative to classical reductometric methods. The substrate is sufficiently stable (pH 5.5, 50°C) and the favorable absorption characteristics of the liberated phenol (pK = 5.5, a/9000 M 1cm 1, pH 5.5 cm 16000 at pH 6.5) allow sensitive, continuous measurements. Kinetic parameters for some of these substrates and enzymes were determined K values were in the mM range for the lactoside (CBH I, EG I, EGD) and were at least 10 times lower for the cellobioside turnover numbers ranged from 1 (CBH I, cellobioside) to 300 min-1 (EG D, cellobioside) (25°C). 

In the presence of chlorides an even larger number of transients could be observed, indicating that additional nucleation sites were activated. Measurements in solutions... 

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