Cascade Reactions for Assaying Transketolase Activity by In Vivo Selection

The relative specific activity data was converted to gray scale value. The specific activity of TK toward 50 mM glycolaldehyde was used as 100% reference, a, 50 mM methanal b, 50 mM glycolaldehyde c, 50 mM D-glyceraldehyde d, 

To conclude, this pH-based assay holds promise as a very useful tool for the screening of novel TK enzymes for their substrate tolerance and modification by directed evolution that offers simplicity, speed, high sensitivity, and low cost. 

Cascade Reactions for Assaying Transketoiase Activity by In Vivo Selection 

The principle of an in vivo selection test may enable the direct detection of foreign TK activity such as that from yeast on nonnatural substrates in E. coU host cells. This type of metaboUc assay was developed for using specially designed synthetic compounds (probes 16a and 16b) that combine a ketose moiety, potentiaUy recognized for selective cleavage by TK, and the side chain of a proteinogenic amino acid [40, 41]. 

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