Cleavage of Aliphatic α‑Hydroxy Ketones by Evolved Transketolase from Geobacillus stearothermophilus

• Published in: ACS catalysis Vol. 12; no. 6; pp. 3566 - 3576
• Main Authors: Casajus, Hubert, Lagarde, Aurélie, Nauton, Lionel, Ocal, Nazim, Leremboure, Martin, Fessner, Wolf-Dieter, Duguet, Nicolas, Charmantray, Franck, Hecquet, Laurence
• Format: Journal Article
• Language: English
• Published: American Chemical Society 18.03.2022
• Subjects: Chemical Sciences; C−C bond cleavage; mutagenesis; α-hydroxy ketones; transketolase; biocatalysis
• ISSN: 2155-5435; 2155-5435
• DOI: 10.1021/acscatal.1c05140

The reaction catalyzed by ubiquitous thiamine pyrophosphate-dependent transketolase engaged in cells in the pentose phosphate pathway can be applied in vitro to the cleavage of aliphatic α-hydroxy ketones with thermostable transketolase variants from Geobacillus stearothermophilus obtained through rational design. The simple variant F435I gave the best activity toward (3S)-1,3-dihydroxyhexan-2-one 3, leading to the corresponding product with 92% yield after only 2 h of reaction time. Three triple variants H102L/H474 (S, G, or A)/F118I were found to cleave (±)-4-hydroxyhexan-3-one 6, giving the corresponding product with 90, 82, and 79% yield, respectively, after 24 h, whereas wild-type transketolase was almost ineffective. This biocatalytic strategy offers a promising one-step alternative to other multienzyme or chemical ways for the cleavage of aliphatic α-hydroxy ketones.