Thiamin diphosphatases

The reaction mixture was composed of 50 p.L of membrane preparation, 10 mM Hepes-Tris buffer (pH 6.8), 1.5 mM MgQ2, 1.5 mM EGTA, and 0.1 mM thiamine triphosphate in a total volume of 100 fiL. After 15 minutes of incubation at 25°C, the reaction was stopped by addition of 500 fiL of 6% trichloroacetic acid. The supemate obtained by centrifugation was extracted with 4 volumes of diethyl ether. The thiamine derivatives were transformed into fluorescent thiochromes by the addition of 50 fiL of oxidant [4.3 mJW K3Fe(CN)6 in 15% NaOH] to 80 fiL of sample. Thiamine diphosphatase activity was minimized by using magnesium as the metal and EGTA to chelate calcium. 

Rao VL, Richardson JS, Butterworth RE (1993) Decreased activities of thiamine diphosphatase in frontal and temporal cortex in Alzheimer s disease. Brain Res 631(2) 334-336 Rebec GV, Conroy SK, Barton SJ (2006) Hyperactive striatal neurons in symptomatic Huntington R6/2 mice variations with behavioral state and repeated ascorbate treatment. Neuroscience 137(l) 327-336... 

S ATP + 2-methyl-4-amino-5-pho.sphomethylpyrimidine <1, 2, 3> (<1> specific for ATP [1] <3> enzyme has both 2-methyl-4-amino-5-hydroxy-methylpyrimidine phosphate kinase and thiamin-phosphate diphosphatase activities, involved in thiamine biosynthesis [3]) (Reversibility <1, 2, 3> [1,2, 3]) [1,2,3]... 

Histochemical studies on Raillietina (.Raillietina) johri (Cestoda Davaineidae). II. Nucleoside diphosphatase and thiamine pyrophosphatase. Journal of Helminthology, 53 261-3. 

It is likewise of equal interest that the Golgi apparatus is the site of many hydrolase activities such as alkaline and acid phosphatases, j8-glu-curonidase, nucleoside diphosphatase, and thiamine pyrophosphatase. 

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