Purity and activity of enzyme

Purity and activity of enzyme Enzyme reactions depend 

The purity of the enzyme is reflected by its specificity for a panel of substrates. Many preparations may contain contaminating activities and the number of crystallizations indicated for commercial preparations is a poor criterion for purity. The absence of proteases is important to maintain maximum stability of the preparations. Contaminating microorganisms very often produce proteases however, the addition of preservatives may interfere with enzyme activity. For example, POase is extremely sensitive to both contaminating bacteria and NaNs, Sometimes, enzymes can be stabilized by the addition of substrate homologues. 

Lyophilized enzymes usually contain residual water, which is not 

Determination of enzyme activity with a coupled enzyme reaction Sometimes an indicator reaction is necessary to establish 

If the decrease in S or the increase in P cannot be established, a second enzyme, E , may be introduced into the system to produce P which is measurable. E2, which transforms P into P, is faced with low initial P concentration. At a given moment, however, a steady state is obtained, i.e. the two reaction rates become equal. 

---