The mechanism of a one-substrate transketolase reaction
نویسندگان
چکیده
منابع مشابه
Mechanism of Action of Transketolase
For detailed studies on the mode of action of an enzyme a readily available source and a convenient method of preparation are of distinct advantage. Accessible sources such as bakers’ yeast (1) and spinach leaves (2) have, therefore, been used for large-scale preparations of transketolase in spite of the fact that extracts of Escherichia coli, in which the cleavage of ribose-5-P to triose-P was...
متن کاملA coupled reaction catalyzed by the enzymes transketolase and transaldolase.
The formation of pentose phosphate from hexose monophosphate involves either the oxidative pathway from glucose 6phosphate through 6-phosphogluconate or the series of nonoxidative transfer reactions catalyzed by transketolase and transaldolase, in which sedoheptulose 7-phosphate is an intermediate (1). In mammalian tissues the nonoxidative pathway appears to play a major role (2-5), accounting ...
متن کاملMechanism-Based Studies of the Active Site-Directed Inhibition and Activation of Enzyme Transketolase
Derivatives of phenyl-keto butenoic acids have been reported to be inhibitors of pyruvate decarboxylase, (PDC). The inhibition of transketolase, a thiamine requiring enzyme such as PDF, by meta nitrophenyl derivative of 2-oxo-3-butenoic acid (MNPB) is reported here. These studies indicate that the inhibitor binds to the enzyme at the active site. A two-step inhibition was observed, first th...
متن کاملTransketolase reaction under credible prebiotic conditions.
A transketolase reaction was catalyzed by cyanide ion under prebiotic conditions instead of its modern catalyst, thiamine pyrophosphate (TPP). Cyanide ion converted fructose plus glyceraldehyde to erythrose plus xylulose, the same products as are formed in modern biochemistry (but without the phosphate groups on the sugars). Cyanide was actually a better catalyst than was TPP in simple solution...
متن کاملRational substrate and enzyme engineering of transketolase for aromatics.
The uses of 3-formylbenzoic acid and 4-formylbenzoic acid as molecular probes along with previous and new transketolase mutants revealed the factors governing the rate of reaction between transketolase and aromatic aldehydes. The novel α,α-dihydroxyketones were produced at 15 to 30-fold higher yields and up to 250-fold higher specific activities with D469T TK when compared to those obtained for...
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ژورنال
عنوان ژورنال: Bioscience Reports
سال: 2020
ISSN: 0144-8463,1573-4935
DOI: 10.1042/bsr20180246