Related Experiment Video
Updated: Mar 9, 2026

Rapid One-step Enzymatic Synthesis and All-aqueous Purification of Trehalose Analogues
Published on: February 17, 2017
Second-Generation Engineering of a Thermostable Transketolase (TKGst ) for Aliphatic Aldehyde Acceptors with Either
Chaoqiang Zhou1, Thangavelu Saravanan2, Marion Lorillière3,4
1State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Meilong Road 130, 200237, Shanghai, P.R. China.
Abstract:
The transketolase from Geobacillus stearothermophilus (TKGst ) is a thermostable enzyme with notable high activity and stability at elevated temperatures, but it accepts non-α-hydroxylated aldehydes only with low efficiency. Here we report a protein engineering study of TKGst based on double-site saturation mutagenesis either at Leu191 or at Phe435 in combination with Asp470; these are the residues responsible for substrate binding in the active site. Screening of the mutagenesis libraries resulted in several positive variants with activity towards propanal up to 7.4 times higher than that of the wild type. Variants F435L/D470E and L191V/D470I exhibited improved (73 % ee, 3S) and inverted (74 % ee, 3R) stereoselectivity, respectively, for propanal. L191V, L382F/E, F435L, and D470/D470I were concluded to be positive mutations at Leu191, Leu382, Phe435, and Asp470 both for activity and for stereoselectivity improvement. These results should benefit further engineering of TKGst for various applications in asymmetric carboligation.
Related Concept Videos
Acetals and Thioacetals as Protecting Groups for Aldehydes and Ketones
In the presence of multiple functional groups, when selective reduction of one group over the other is desired, groups like aldehydes and ketones that form acetals...
Regioselective Formation of Enolates
Aldehydes and Ketones to Alkenes: Wittig Reaction Overview
Reactions of Aldehydes and Ketones: Baeyer–Villiger Oxidation
The carbonyl center is activated by...
Aldol Condensation with β-Diesters: Knoevenagel Condensation
Ketones with Nonenolizable Aromatic Aldehydes: Claisen–Schmidt Condensation
As the self-condensation of ketones is generally not favored in basic conditions, the self-condensed products do not form in the reaction between ketones and benzaldehyde. The general reaction of Claisen–Schmidt...

