Detection of cellular metabolites by redox enzymatic cascades

Abstract

Detection of cellular metabolites that are disease biomarkers is important for human healthcare monitoring and assessing prognosis and therapeutic response. Accurate and rapid detection of microbial metabolites and pathway intermediates is also crucial for the process optimization required for development of bioconversion methods using metabolically engineered cells. Various redox enzymes can generate electrons that can be employed in enzyme‐based biosensors and in the detection of cellular metabolites. These reactions can directly transform target compounds into various readout signals. By incorporating engineered enzymes into enzymatic cascades, the readout signals can be improved in terms of accuracy and sensitivity. This review critically discusses selected redox enzymatic and chemoenzymatic cascades currently employed for detection of human‐ and microbe‐related cellular metabolites including, amino acids, d‐glucose, inorganic ions (pyrophosphate, phosphate, and sulfate), nitro‐ and halogenated phenols, NAD(P)H, fatty acids, fatty aldehyde, alkane, short chain acids, and cellular metabolites.

A high catalytic efficiency and chemotolerant formate dehydrogenase from Bacillus simplex

“…oxidoreductases, [40] or enzymes involved with H 2 O 2 /reactive intermediates, for instance, flavin-dependent halogenase [41] and OleT JE decarboxylase cytochrome P450. [42] These enzymes are widely applied in biocatalysis, ranging from valuable compound synthesis [43] to detection [26,44] and bioremediation. [24] In conclusion, this study reports the biochemical characterization of a novel FDH that has high formate oxidation activity.…”

“…The high oxidative reagent tolerance of BsFDH might be valuable for synthesis reactions involving H 2 O 2 byproducts, for instance, flavin‐dependent monooxygenases [ 39 ] and cytochrome P450 oxidoreductases, [ 40 ] or enzymes involved with H 2 O 2 /reactive intermediates, for instance, flavin‐dependent halogenase [ 41 ] and OleT JE decarboxylase cytochrome P450. [ 42 ] These enzymes are widely applied in biocatalysis, ranging from valuable compound synthesis [ 43 ] to detection [ 26,44 ] and bioremediation. [ 24 ]…”

Intermediate product control in cascade reaction for one‐pot production of ε‐caprolactone by Escherichia coli

“…Further benefits of cascade reaction include the possible handling of unstable intermediates, the control of unfavorable reaction equilibria and the increase of atom economy and overall yields. [4][5][6][7] Nevertheless, high-efficiency cascade reaction requires optimized reaction parameters and perfect process control to transform the intermediates into the final product rapidly. As a reason, the ratio between multiple enzymes in reaction has to be tuned carefully.…”

“…Further benefits of cascade reaction include the possible handling of unstable intermediates, the control of unfavorable reaction equilibria and the increase of atom economy and overall yields. [ 4–7 ]…”