Pyruvic oxidase and

A FIA system has been proposed for the CL detection of phosphate based on an enzymatic reaction and the application of a subsequent luminol reaction [41], The system consists of an immobilized pyruvate oxidase column, a mixing chamber for the CL reaction, and a PMT. H202 is generated by the reaction of phosphate and pyruvate oxidase and then reacts with luminol and HRP, producing... 

A carboxylic side-chain of a glutamic acid (which is conserved in pyruvate decarboxylases, pyruvate oxidase and transketolase) forms a hydrogen bond to l N of ThDP, and thus keeps this nitrogen in the protonated form. The positive charge is delocalized to the 4 -NH2-group, making it possible for it to act as a proton donor [35,60]. 

The antidotal properties of BAL arc a.ssociatcd with the property of heavy metals to react with sullliydryl (SH) groups in proteins (e.g., tlie en/.yme pyruvate oxidase) and interfere with their normal function. 1.2-Dilhiol compounds such as BAL compete effectively with such proteins for the metal by reversibly forming metal ring compounds of the following type ... 

A thiamin diphosphate binding fold revealed by comparison of the crystal structures of transketolase, pyruvate oxidase and pyruvate decarboxylase. Structure 1, 95-103. 

Magnesium is closely associated with calciiun and phosphorus. About 70 per cent of the total magnesium is found in the skeleton but the remainder, which is distributed in the soft tissues and fluids, is of crucial importance to the well-being of the animal. Magnesium is the commonest enzyme activator, for example in systems with thiamin pyrophosphate as a cofactor, and oxidative phosphorylation is reduced in magnesium deficiency. Magnesium is an essential activator of phosphate transferases (e.g. creatine kinase) and it activates pyruvate carboxylase, pyruvate oxidase and reactions of the tricarboxylic acid cycle therefore, it is essential for the... 

Pyruvate oxidase and pyruvate ferredoxin oxidoreductase catalyse the oxidative decarboxylation of pyruvate and forms a radical intermediate. 

Horecker has isolated from spinach leaves a diphosphothiaminopro-tein enzyme which catalyzes the above transketolation between the two pentosephosphates. It is of interest that diphosphothiamine has been shown to be the prosthetic group of all acetoin-forming enzymes such as pyruvic oxidase and yeast carboxylase. 

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