Thiamine triphosphate and thiamine triphosphatase activities: from bacteria to mammals

In most organisms, the main form of thiamine is the coenzyme thiamine diphosphate. Thiamine triphosphate (ThTP) is also found in low amounts in most vertebrate tissues and can phosphorylate certain proteins. Here we show that ThTP exists not only in vertebrates but is present in bacteria, fungi, plants and invertebrates. Unexpectedly, we found that in Escherichia coli as well as in Arabidopsis thaliana, ThTP was synthesized only under particular circumstances such as hypoxia (E. coli) or withering (A. thaliana). In mammalian tissues, ThTP concentrations are regulated by a specific thiamine triphosphatase that we have recently characterized. This enzyme was found only in mammals. In other organisms, ThTP can be hydrolyzed by unspecific phosphohydrolases. The occurrence of ThTP from prokaryotes to mammals suggests that it may have a basic role in cell metabolism or cell signaling. A decreased content may contribute to the symptoms observed during thiamine deficiency.Received 7 March 2003; received after revision 11 April 2003; accepted 14 April 2003     

Über den Vitamin-B12-Gehalt von Organen verschieden ernährter Ratten

Summary Adult, male rats bred for over 10 generations on a soy meal-corn-diet had vitamin B₁₂ values of liver and kidney about 10 times lower than the controls. If the deficient ration was supplemented with 5µg/kg of B₁₂, these values were still about 1/5 of the controls. 3 weeks on the deficient diet lowered the B₁₂ levels in the livers and kidneys of previously undepleted rats to about 1/2, and a similar diet containing 0.1% of iodized casein lowered these levels to about 1/3 of the normal values but did not lower the B₁₂-concentration of organs of already deficient rats.Rats bred on the deficient diet and receiving for 1 month a supplement of 30µg/kg of vitamin B₁₂ or the stock diet with a similar B₁₂-content, had normal B₁₂-levels in livers and kidneys.     

Wirkung der Glutaminsäure auf die experimentelle Isoniazid-Schädigung peripherer Nerven bei Ratten

Summary Glutamic acid does not, either in small or in large doses, inhibit the degeneration of the medullary sheath of peripheral nerves in rats, induced within 15 days by addition of 0.25% of isoniazid to their diet. The detoxicating effect of glutamic acid, as described byCedrangolo ¹, thus only applies to the general toxic symptoms of the acute INH-intoxication, as is the case for vitamins B₂, B₁₂, A, E, K, and niacinamide.     

Der Vitamingehalt der Moste verschiedener Rebenarten und -sorten

Summary The vitamins pyridoxine, pantothenic acid, niacin, and biotin in the musts of about 100 different species and varieties of vines were determined microbiologically. Musts of vines of the speciesVitis vinifera differed from wild species ofVitis by a lower amount of pyridoxine and pantothenic acid. The low content of these vitamins is suspected of being coupled with good cultural characters.      

Active transport of [32P]thiamine diphosphate inEscherichia coli

Summary Active uptake of [³²P]thiamine diphosphate byE. coli was analyzed using an improved method of gel filtration chromatography. The radioactive coenzyme was accumulated without dephosphorylation. From this result it was concluded that thiamine kinase is not involved in the membrane transport of thiamine inE. coli.We are indebted to Miss M. Abe for her technical assistance.     

Influence of hydroxyurea,ellman's reagent and potassium ferricyanide on the radiosensitivity ofEscherichia coli

Zusammenfassung Zwei thiolbindende Agentien, K₃Fe(CN)₆ undEllmans Reagens wie auch der die DNA-Synthese hemmende Oxyharnstoff wurden als mögliche bakterielle Sensibilisatoren für Röntgenstrahlen untersucht. K₃Fe(CN)₆ und Oxyharnstoff im Medium können die Bakterien für die Inaktivierung durch Röntgenstrahlen besonders sensibilisieren (stärker mitE. coli B/r als mitE. coli B _s-1).     

Elaboration of vitamin B12 byEscherichia coli

Résumé Les auteurs ont constaté l'absence de la vitamine B₁₂ dans le corps 1° deE. coli 113-3, 2° de son parent prototrophique et 3° dans la souche sauvage. Le titre de B₁₂ dans le milieu de culture s'est trouvé fortement augmenté par la méthionine, dans le cas de la souche sauvage uniquement. En ajoutant de la cyanocobalamine on a obtenu dans les trois cas une augmentation de désoxyribosides.

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This work was supported by Grants A-1800 and A-1231 from the U. S. Public Health Service and Grants-in-Aid from the Loomis Foundation, the American Cancer Society, and the Nat. Ass. for Mentel Health.     

Inhibition of thiamine synthesis by vitamin B12 in wild strains ofEscherichia coli

Zusammenfassung Zusatz von Vitamin B₁₂ in Kulturnährböden hemmt die Thiamin-Biosynthese von frisch isoliertenE.-coli-Stämmen. Diese Hemmung steht im Verhältnis zur zugesetzten Menge von Vitamin B₁₂.     

Zum Problem des Stoffwechsels der Brenztraubensäurein vivo

Summary In the end-stage of progressive alloxan diabetes of the rabbit we have been able to overcome the acute pyruvic acidosis by the use of phosphorylated vitamin B₁ (cocarboxylase) together with vitamin B₂, while it is impossible to cure the endogen hyperpyruviæmia with simple vitamin B₁. The superiority of the coferment over the vitamin, which is only effective at the beginning of the decompensation, implies the existence of a disturbance in the phosphorylation during the crisis of diabetic metabolism. We have been successful in preventing the inevitable death in coma of diabetic rabbits by doses of cocarboxylase + riboflavin, and we were able to keep them alive by continuous doses of insulin together with vitamin B₁ and B₂.

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Ein Teil der Experimente wurde mit Unterstützung der Roche-Studienstiftung durchgeführt.     

Thiamine diphosphatase in rat small intestine

Summary TDPase is located mostly in the proximal portion of the small intestine and its activity, like that of ALPase, decreased markedly in thiamine deficiency. The decreased enzyme activities were restored after thiamine or vitamin D₃. Kinetic and other studies of the purified enzyme indicated the identity of the two enzymes.Acknowledgment. We thank Miss.T. Yagura and Miss.H. Kuroda for technical assistance.