Thiamine diphosphate -dependent enzyme

Other thiamine diphosphate-dependent enzymes have recently been scrutinized for their preparative value [166]. Although pyruvate decarboxylase (PDC) (EC 4.1.1.1)... 

Figure 10.40 Stereocomplementary acyloin syntheses based on the carboligation capacity of thiamine diphosphate-dependent enzymes.

Berthold CL, P Moussatche, NGJ Richards, Y Lindqvist (2005) Structural basis for activation of the thiamin diphosphate-dependent enzyme oxalyl-CoA decarboxylase by adenosine diphosphate. J Biol Chem 280 41645-41654. 

The requirement for NAD+ is to reoxidize the lipoic acid carrier. It is worth mentioning that the pyruvate acetaldehyde conversion we considered at the end of the glycolytic pathway involves the same initial sequence, and pyruvate decarboxylase is another thiamine diphosphate-dependent enzyme. 

C-C-Bonding Microbial Enzymes Thiamine Diphosphate-Dependent Enzymes and Class I Aldolases... 

M. S. Hasson, A. Muscate, M. J. McLeish, L. S. Polovnikova, J. A. Gerlt, G. L. Kenyon, G. A. Petsko, D. Ringe, The crystal structure of benzoylformate decarboxylase at 1.6 A resolution, diversity of catalytic residues in thiamin diphosphate-dependent enzymes. Biochemistry 1998, 37, 9918-9930. 

A Thiamine Diphosphate-Dependent Enzymes Multi-purpose Catalysts in Asymmetric Synthesis... 

By 1998, X-ray structures had been determined for four thiamin diphosphate-dependent enzymes (1) a bacterial pyruvate oxidase,119120 (2) yeast and bacterial pyruvate decarboxylases,121 122c (3) transketolase,110123124 and (4) benzoylformate decarboxylase.1243 Tire reactions catalyzed by these enzymes are all quite different, as are the sequences of the proteins. However, the thiamin diphosphate is bound in a similar way in all of them. 

The pathway also operates in some bacteria and apparently is the sole source of isoprenoid compounds for the unicellular alga Scenedesmus.28 The pathway is outlined in Fig. 22-2. Pyruvate is decarboxylated by a thiamin diphosphate-dependent enzyme,29 and the resulting enamine is condensed with D-glyceraldehyde 3-phosphate to form 1-deoxyxylulose 5-phosphate.28, i0 31a The latter undergoes an isomeroreductase rearrange-... 

Results of a kinetic study of enamine formation by C(2a)-proton abstraction from 2-benzylthiazolium salts (88) have implications for mechanistic studies of the thiamin diphosphate-dependent enzymes which feature protonation of the enamine/C(2a)-carbanion.151 The primary isotope effect for deprotonation of (88a) is kiw/kro = 4-6 and the values estimated for C(2a)—H pXa are 15.0-15.5 and 15.7 for (88a) and (88b), respectively. A minimum effective molarity of 4500 M has been estimated for reprotonation of the enamine (89b) derived from (88b) by benzoylformate decarboxylase. Directed aromatic metallation reactions have been reviewed.152... 

Enantiopure, bifunctional acyloins (a-hydroxy ketones) are versatile intermediates in natural product synthesis (also see Sect. 2.3, Fig. 11). In nature, the formation of a-hydroxy ketones is efficiently catalyzed by thiamine diphosphate-dependent enzymes transketolases, decarboxylases, and other lyases, such as BALs. A great portfolio of biotransformations, especially with benzaldehyde derivatives as starting materials, were realized [204]. 

Muller M, Gocke D et al (2009) Thiamin diphosphate in biological chemistry exploitation of diverse thiamin diphosphate-dependent enzymes for asymmetric chemoenzymatic synthesis. FEBS J 276 2894-2904... 

Pohl M, Lingen B et al (2002) Thiamin-diphosphate-dependent enzymes new aspects of asymmetric C-C bond formation. Chem Eur J 8 5288-5295... 

Possible role of thiamin diphosphate-dependent enzymes in... 

Are enamine mimics general transition-state analogs for thiamin diphosphate-dependent enzymes ... 

In a very imaginative piece of research Frost and coworkers have developed a plasmid-based method for synthesizing aromatic amino acids, by incorporating the genes that code for the enzymes that perform the series of conversions from D-fructose-6-phosphate to D-erythrose-4-phosphate to 3-deoxy-D-arabinoheptulosonic acid-7-phos-phate (DAHP) near each other on a plasmid that can be transformed in E. coli. The enzymes are the thiamin diphosphate-dependent enzyme transketolase in the nonoxida-tive pentose shunt and DAHP synthase. The DAHP is then converted to the cyclic dehydroquinate, a precursor to all aromatic amino acids L-Tyr, L-Phe and L-Trp165,166 (equation 27). 

The synthetic potential of thiamin diphosphate dependent enzymes is now recognized and has been reviewed recently.84-85 TK has been isolated from... 

HerouxM and Butterworth RF (1995) Regional alterations of thiamine phosphate esters and of thiamine diphosphate-dependent enzymes in relation to function in experimental Wernicke s encephalopathy. Neurochemistry Research 20,87-93. 

Hohmann S and Meacock PA (1998) Thiamin metabolism and thiamin diphosphate-dependent enzymes in the yeast Saccharomyces cerevisiae. genetic regulation. Bio-chimica et Biophysica Acta 1385, 201-19. 

Schenk G, Duggleby RG, and Nixon PF (1998) Properties and functions of the thiamin diphosphate dependent enzyme transketolase. International Journal of Biochemistry and Cell Biology 30,1297-1318. 

Biomimetic Synthesis of Solerone. We applied pyruvate decarboxylase [EC 4.1.1.1] (PDC) as key enzyme for the biomimetic synthesis elucidating the formation of solerone 1 figure 1). The thiamine diphosphate depending enzyme from Saccharomyces cerevisiae is responsible for the decarboxylation of pyruvate in the course of alcoholic fermentation. After loss of carbon dioxide from 2-oxoacids the resulting aldehyde is released. Alternatively, the cofactor-bound decarboxylation product can react with a further aldehyde. By the latter acyloin condensation a new carbon-carbon bond will be formed, thus opening a biosynthetic way to a-hydroxy carbonyl compounds 11J2). 

Y. Lindqvist, G. Schneider, U. Ermler, and M. Sundstrom. 1992. Three-dimensional structure of transketolase, a thiamine diphosphate dependent enzyme, at 2.5 A resolution EMBO J. 11 2373-2379. (PubMed)... 

G. Schenk, R. Layfield, J.M. Candy, R.G. Duggleby, and P.F. Nixon. 1997. Molecular evolutionary analysis of the thiamine-diphosphate-dependent enzyme, transketolase J. Mol. Evol. 44 552-572. (PubMed)... 

Arjunan, P., et al. (1996). Crystal structure of the thiamin diphosphate-dependent enzyme pyruvate decarboxylase from the yeast saccharomyces cerevisiae at 2.3 A Resolution. J. Mol. Biol. 256, 590-600... 

An elegant work is reported concerning the oxidation of 2-alkyl and 2-benzylthia-zolium salts, in the presence of a base, with the scope of finding a structural relationship for the thiamine-bound intermediate which intervene in the oxidative decarboxylation of a-ketoacids catalysed by thiamin diphosphate-dependent enzymes. 2-Alkyl and 2-benzylthiazolium salts, which are not electroactive, can be transformed into electroactive species by treatment with the base (trimethylsilyl)amide. Subsequent anodic oxidation affords the corresponding symmetrical dimers, by an EC mechanism (Scheme 72). As expected, the stabilizing effect of the substituents R, R at the a-carbon on the radical cation follows the order H < Me < OMe. When R is aryl, electron-donating p-substituents again enhance the enamine oxidation. 

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