Enzymatic Synthesis of 3-Deoxy-d-manno-octulosonate 8-Phosphate, 3-Deoxy-d-altro-octulosonate 8-Phosphate, 3,5-Dideoxy-d-gluco(manno)-octulosonate 8-Phosphate by 3-Deoxy-d-arabino-heptulosonate 7-Phosphate Synthase
摘要:
The phenylalanine-sensitive 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAH 7-P) synthase (phe), a key enzyme involved in the biosynthesis of the aromatic amino acid phenylalanine, expressed by the Escherichia coli gene aroG, which catalyzes the condensation of D-erythrose 4-phosphate with phosphoenolpyruvate (PEP) to give DAH 7-P, was cloned into the expression vector pT7-7 for overexpression in E. coli. Purified enzyme from this expression system was used to demonstrate that DAH 7-P synthase (phe) also catalyses the aldol-type condensation of PEP with the 5-carbon analogues D-arabinose 5-phosphate, D-ribose 5-phosphate, and 2-deoxy-D-ribose 5-phosphate to yield 3-deoxy-D-manno-octulosonate 8-phosphate, 3-deoxy-D-altro-octulosonate 8-phosphate, and 3,5-dideoxy-D-gluco(manno)-octulosonate 8-phosphate, respectively, as determined by H-1 NMR and other standard analytical methods. The kinetic parameters, K-m and V-max, for these reactions were determined. The 3- and 6-carbon phosphorylated monosaccharides, D,L-glyceraldehyde 3-phosphate and D-glucose 6-phosphate, as well as the nonphosphorylated 5-carbon analogues D-arabinose 5-phosphate, D-ribose 5-phosphate, and 2-deoxy-D-ribose 5-phosphate were not substrates.
Structure-Based mutagenesis approaches toward expanding the substrate specificity of d-2-Deoxyribose-5-phosphate aldolase
作者:Grace DeSantis、Junjie Liu、David P Clark、Andreas Heine、Ian A Wilson、Chi-Huey Wong
DOI:10.1016/s0968-0896(02)00429-7
日期:2003.1
2-Deoxyribose-5-phosphate aldolase (DERA, EC 4.1.2.4) catalyzes the reversible aldol reaction between acetaldehyde and D-glyceraldehyde-3-phosphate to generate D-2-deoxyribose-5-phosphate. It is unique among the aldolases as it catalyzes the reversible asymmetric aldol addition reaction of twoaldehydes. In order to expand the substrate scope and stereoselectivity of DERA, structure-based substrate design as well
Inagaki, Journal of Biochemistry, 1940, vol. 32, p. 63,74,75
作者:Inagaki
DOI:——
日期:——
Deoxyribose-5-phosphate aldolase as a synthetic catalyst
作者:Carlos F. Barbas、Yi Fong Wang、Chi Huey Wong
DOI:10.1021/ja00161a064
日期:1990.2
Improvement of aldehyde tolerance and sequential aldol condensation activity of deoxyriboaldolase via immobilization on interparticle pore type mesoporous silica
Deoxyriboaldolase from Klebsiella pneumonia (KpDERA) was immobilized on interparticle pore type mesoporous silica (IMS), which consists of aggregates of hexagonally close-packed silica nanoparticles. Incubation of the free KpDERA in 300 mM acetaldehyde resulted in a decrease in the free enzyme activity to 20% of the initial activity after incubation for 30 min. No activity was observed after 90 min incubation. In contrast, the IMS-immobilized KpDERA retained more than 50% of its activity after 30 min and 11% activity after 90 min incubation. The product yield of a sequential aldol condensation reaction, which is central to the production of pharmaceutically important intermediates, was found to be higher for IMS-immobilized KpDERA than for the free enzyme. These results suggest the potential utility of IMS as an immobilization support for DERA. (c) 2010 Elsevier B.V. All rights reserved.
Pricer; Horecker, Biochemical Preparations, 1962, vol. 9, p. 35