olizing this substrate in the presence of ATP1 to form a mixture of n-ribose 5-phosphate and n-ribulose 5-phosphate. Although neither n-xylose 5-phosphate nor n-xylulose 5-phosphate was found, these authors postulated the latter as an intermediate upon the observation that n-xylulose was phosphorylated more rapidly than n-xylose. n-Xylulose 5-phosphate was first isolated and identified as a pro...

Sedoheptulose-7-phosphate, originally identified as a product of photosynthesis in algae and higher plants (3), has been shown to arise by the action of transketolase on pentose phosphate (4, 5). This reaction occurs in a wide variety of animal (5, 6), plant (5, 7), and microbial cells (8-lo), and evidence has been obtained that the heptulose ester is an intermediate in the formation of hexose ...

The evolutionary relationships of the thiamine pyrophosphate (TPP) dependent family of enzymes was investigated by generation of a neighbor joining (NJ) phylogenetic tree using sequences from the conserved pyrophosphate (PP) and pyrimidine (Pyr) binding domains of 17 TPP-dependent enzymes. This represents the most comprehensive analysis of TPP-dependent enzyme evolution to date. The phylogeny w...

Transketolase has significant industrial potential for the asymmetric synthesis of carboncarbon bonds with new chiral centres. Variants evolved on propanal were found previously with nascent activity on polar aromatic aldehydes 3-formylbenzoic acid (3-FBA), 4-formylbenzoic acid (4-FBA), and 3-hydroxybenzaldehyde (3-HBA), suggesting a potential novel route to analogues of chloramphenicol. Here w...

Probiotic bacterial strains have been shown to enhance the health of the host through a range of mechanisms including colonization, resistance against pathogens, secretion of antimicrobial compounds and modulation of the activity of the innate immune system. Lactobacillus salivarius UCC118 is a well characterized probiotic strain which survives intestinal transit and has many desirable host-int...

The partially purified transketolase from each of eight well-nourished patients with Alzheimer's disease contained significantly less heat-stable component with a significantly longer half-life of heat inactivation than that from eight controls. Immunochemical studies utilizing antibodies to the purified human liver transketolase did not distinguish between red blood cell transketolases of pati...

The natural ly occurring beetle pheromone (+)-cxo-brevicomin was synthesized by a strategy combining chemical and enzymatic steps. The commercial ly avai lable enzyme transketolase (EC 2.2.1.I) catalyzed the condensation of B-hydroxypyruvic acid ancl 2-hydroxybutyraldehyde to furnish the central intermediate in the sequence, optically active hydroxyketone 5. A short sequence converted ketose 5 ...

Thiamine deficiency causes a decrease in transketolase activity and an increase in thiamine pyrophosphate (TPP) effect on the erythrocytes. The objective of this experiment was to determine if ruminal acidosis alters erythrocytic transketolase enzyme activity as an indicator of thiamine level in feedlot cattle. A total of 65 feedlot cattle (1–2 years old) were fed either high concentrate diet (...

Here, we present an immobilized enzyme cascade in a basket-type reactor allowing one-pot, two-step enzymatic synthesis of L-erythrulose from D-serine and glycolaldehyde. Three enzymes, D-amino acid oxidase Rhodotorula gracilis (DAAORg), catalase bovine liver (CAT), transketolase Geobacillus stearothermophilus (TKgst) were covalently on silica monolithic pellets, characterized by open structure ...

Ascidians, especially those belonging to the Ascidiidae, are known to accumulate extremely high levels of vanadium in vanadocytes, one type of blood (coelomic) cell. Vanadium, which exists in the +5 oxidation state in seawater, is accumulated in the vanadocytes and reduced to the +3 oxidation state. We have been trying to characterize all of the polypeptides specific to vanadocytes and to speci...