Enzyme-catalyzed synthesis of carbohydrates: synthetic potential of transketolase
摘要:
The synthetic potential of yeast or spinach transketolases was studied, using hydroxypyruvate as a donor substrate and 31 aldehydes as acceptors. All of them react, including aromatic, heteroaromatic and alpha,beta unsaturated aldehydes.
Here we have characterized the first transketolase (TK) from a thermophilic microorganism, Geobacillus stearothermophilus, which was expressed from a synthetic gene in Escherichia coli. The G. stearothermophilus TK (mTKgst) retained 100% activity for one week at 50 °C and for 3 days at 65 °C, and has an optimum temperature range around 60–70 °C, which will be useful for preparative applications and
Non-α-hydroxylated aldehydes with evolved transketolase enzymes
作者:Armando Cázares、James L. Galman、Lydia G. Crago、Mark E. B. Smith、John Strafford、Leonardo Ríos-Solís、Gary J. Lye、Paul A. Dalby、Helen C. Hailes
DOI:10.1039/b924144b
日期:——
Transketolase mutants previously identified for use with the non-phosphorylated aldehyde propanal have been explored with a series of linear and cyclic aliphatic aldehydes, and excellent stereoselectivities observed.
efficient in situ generation of hydroxypyruvate from d‐serine catalyzed by a d‐amino acid oxidase from Rhodotorula gracilis. This strategy revealed an interesting alternative to the conventional chemical synthesis of hydroxypyruvate starting from toxic bromopyruvate or to the enzymatic transamination from l‐serine requiring an additional substrate as amino acceptor. Hydroxypyruvate thus produced was used