A Photoenzymatic NADH Regeneration System

Abstract

A photoenzymatic NADH regeneration system was established. The combination of deazariboflavin as a photocatalyst with putidaredoxin reductase enabled the selective reduction of NAD+ into the enzyme‐active 1,4‐NADH to promote an alcohol dehydrogenase catalysed stereospecific reduction reaction. The catalytic turnover of all the reaction components was demonstrated. Factors influencing the efficiency of the overall system were identified.

Biocatalysis Fueled by Light: On the Versatile Combination of Photocatalysis and Enzymes

“…C) Setup based on deazariboflavin photocatalyst 14 e and a dual relay system [MV 2+ ( 23 ) and PDR]. [a] Reaction mixtures were irradiated under inert atmosphere with visible light ( λ >420 nm; [b] in the presence of MV 2+ ( 23 ); [c] control with use of stoichiometric amounts of NADH …”

“…The applicability of FNR as a relay enzyme, however, is still rather limited because of its specificity for the phosphorylated nicotinamide cofactors 12 b and 13 b . In a recent contribution the NAD‐dependent putidaredoxin reductase (PDR) from Pseudomonas putida was investigated . 5‐Deazariboflavin (dRf, 14 e , Scheme ) was identified as the most suitable photocatalyst.…”

“…The applicabilityo fF NR as ar elaye nzyme, however,i ss till ratherl imited because of its specificity for the phosphorylated nicotinamide cofactors 12 b and 13 b.I narecent contribution the NAD-dependent putidaredoxin reductase (PDR) from Pseudomonasp utida was investigated. [36] 5-Deazariboflavin (dRf, 14 e,S cheme 2) was identified as the most suitable photocatalyst. Its more negative redoxp otential might accountf or the more efficient reduction of NAD + (12 a)i nr elationt oo ther flavins 14.T he ADH from Rhodococcus ruber (ADH-A) served as the NAD-dependent reductasec atalyzing the enantioselective reduction of structurally different ketones 39 l-39 o (Scheme 7C).…”

“…[ a] Reactionmixtures werei rradiatedu nder inert atmosphere with visible light (l > 420 nm; [ b] in the presence of MV 2 + (23); [c] control with use of stoichiometric amounts of NADH. [36] [42] TOYE/ PETNR [a] 42 b -> 99/89 [42] TOYE/ PETNR [a] 42 c -80/85 [42] TOYE/ PETNR [a] 42 d 9/376 8/22 [42] TOYE/ PETNR [a] 42 e 6/857 3/65 [42] TOYE/ PETNR [a] 42 f > 99/ > 99 82/10 [42] TOYE/ PETNR [a] 42 g 98/ > 99 6/5 [42] 16 a -TEA Ts OYE/YqjM 42 h > 99 76/84 [43] Ts OYE/YqjM 42 c -34/32 [43] N-CD 22 TEA Ts OYE 42 h 93 86 [44]…”

Green Catalysts: Applied and Synthetic Photosynthesis

“…Another biohybrid approach to CO2 reduction involves the light driven production of NADH [170] or reduced MV [171] to drive the formation of formic acid by formate dehydrogenase. A variety of light absorbers can be used in these systems including organic dyes such as porphyrins [170,172], xanthenes [173] , flavins [174] , and perylenes [175] as well as visible light absorbing semiconductors [171,[176][177][178] , nanostructured materials [179] , polymers [180], and transition metal complexes [181]. If carried out in homogeneous conditions, a sacrificial donor such as EDTA (ethylenediaminetetraacetic acid) or TEOA (triethanolamine) in solution is essential to initiating the photochemical cascade by facilitating the formation of a reducing equivalent from the excited state light absorber.…”