Aminopeptidases reaction times

Aminopeptidases generally require somewhat longer reaction times (60 to 300 s). Commercially available amino peptidases include aminopeptidase M and leucine aminopeptidase. Again, digestion of the -amyloid peptide fragment DAEFR using aminopeptidase would be expected to yield the molecular-ion species ... 

As the graphs in Fig. 8 show, the hydrolysis reaction with the recombinant E. coli cells proceeds much faster than with the P. putida wild-type cells. Therefore, the use of this improved whole-cell aminopeptidase biocatalyst results in significantly shorter reaction times. The reason for this better performance of the newly constructed whole-cell biocatalyst is its much higher aminopeptidase content, reflected by a 25-fold increase in specific activity compared to P. putida. This is caused by improved expression of the P. putida pep A gene, due to the use of a jstrong promoter in combination with a multicopy situation. 

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