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Table 4 Enzymatic activities catalyzed by His-AdhA and Adh0564-His

From: Alcohol dehydrogenases AdhE and AdhB with broad substrate ranges are important enzymes for organic acid reduction in Thermoanaerobacter sp. strain X514

Substrate AdhA
Specific activity
[U mg−1]
Specific activity
[U mg−1]
Alcohol oxidation NAD+ NADP+ NAD+ NADP+
Ethanol 0.0 0.0 n. d 1.21
2-Propanol 0.0 0.05 n. d 0.0
Aldehyde/ketone reduction NADH NADPH NADH NADPH
Acetaldehyde 0.01 1.47 0.29 3.38
Propionaldehyde 0.06 1.23 n. d 8.70
Isobutyraldehyde 0.07 1.23 n. d 8.52
Butyraldehyde 0.09 0.98 n. d 5.21
Phenylacetaldehyde 0.0 0.71 n. d 7.42
Acetone 0.0 0.0 n. d 0.30
2,3-Butanedione 0.0 0.0 n. d 0.0
Aldehyde oxidation (CoA) NAD+ NADP+ NAD+ NADP+
Acetaldehyde 0.0 0.0 n. d 0.05
  1. The His-tagged enzymes were produced in E. coli and purified by affinity chromatography. Activities were determined in 50 mM Tris buffer (pH 7.5) supplemented with 2 mM DTE and 4 µM resazurin. Alcohol (500 mM) or acetaldehyde (10 mM) oxidation was determined with NAD(P)+ (2 mM) as electron acceptor, in the presence or absence of coenzyme A (0.2 mM; AdhE). Aldehyde or ketone (50 mM) reduction to alcohols was determined with NAD(P)H (0.5 mM) as electron donor; and absorption at 340 nm was measured. For details, please see “Methods” section. One unit (U) refers to one µmol of aldehyde reduced or alcohol / aldehyde oxidized per minute. n. d.: not determined