Artificial cascades

The use of P450s in artificial cascade reactions is a rather unexplored research field, and corresponding reports are still very rare in the literature. However, their ability to oxyfunctionalize cheap starting molecules to form valuable compounds, combined with their broad natural functions as essential components in xenobiotics degradation and biosynthesis of secondary metabolites, makes P450 enzymes potential candidates for multi-enzyme processes. 

Artificial cascades performed with isolated enzymes in vitro (cell-free extracts or purified enzymes) provide several advantages compared to artificial cascades in recombinant cells. Multi-enzyme reactions based on isolated enzymes can easily be controlled in a desired maimer, including key factors such as enzyme combination in defined ratios and adjustment of specific reaction component ratios (i.e., cofactors). This allows a more detailed control of the biocatalytic multi-enzyme system in contrast to in vivo cascades where the above-mentioned factors are much more difficult to control. 

The NHase/amidase system in R. erythropolis A4 was also used to transform cyano cyclitols into their carboxyhc acid analogs [21, 22]. As these transformations were coupled to lipase-catalyzed hydrolytic reactions, they are described in detail in the section focused on artificial cascades (see the following paragraphs). 

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