Thiamin pyrophosphate is an essential cofactor that is synthesized de novo by Salmonella typhimurium. In bacteria, the end product of the de novo biosynthetic pathway is thiamin monophosphate, which is then phosphorylated by thiamin-monophosphate kinase (EC 2.7.4.16) to form thiamin pyrophosphate. We have isolated and characterized the thiL gene of S. typhimurium and showed that thiL is a 978-b...

The physiological function for thiaminase II, a thiamin-degrading enzyme, has eluded investigators for more than 50 years. Here, we demonstrate that this enzyme is involved in the regeneration of the thiamin pyrimidine rather than in thiamin degradation, and we identify a new pathway involved in the salvage of base-degraded forms of thiamin. This pathway is widely distributed among bacteria, ar...

This study examines thiamin transport in isolated rat hepatocytes and its relationship to thiamin phosphorylation. In an Na+ medium, [35S]thiamin, 3 microM, was accumulated rapidly by the cells, and a near study state intra-/extracellular distribution ratio of 3 was attained in 1 min. However, the uptake of radioactivity continued to increase with time owing principally to the accumulation of [...

Genes specifying the thiamin monophosphate phosphatase and adenylated thiazole diphosphatase steps in fungal and plant thiamin biosynthesis remain unknown, as do genes for ThDP (thiamin diphosphate) hydrolysis in thiamin metabolism. A distinctive Nudix domain fused to Tnr3 (thiamin diphosphokinase) in Schizosaccharomyces pombe was evaluated as a candidate for these functions. Comparative genomi...

Thiamin and thiamin pyrophosphate (TPP) are well known for their important roles in human nutrition and enzyme catalysis. In this work, we present new evidence for an additional role of these compounds in the protection of cells against oxidative damage. Arabidopsis (Arabidopsis thaliana) plants subjected to abiotic stress conditions, such as high light, cold, osmotic, salinity, and oxidative t...

Thiamin is synthesized by most prokaryotes and by eukaryotes such as yeast and plants. In all cases, the thiazole and pyrimidine moieties are synthesized in separate branches of the pathway and coupled to form thiamin phosphate. A final phosphorylation gives thiamin pyrophosphate, the active form of the cofactor. Over the past decade or so, biochemical and structural studies have elucidated mos...

2-Hydroxyphytanoyl-CoA lyase (abbreviated as 2-HPCL), renamed to 2-hydroxyacyl-CoA lyase (abbreviated as HACL1), is the first peroxisomal enzyme in mammals that has been found to be dependent on TPP (thiamin pyrophosphate). It was discovered in 1999, when studying alpha-oxidation of phytanic acid. HACL1 has an important role in at least two pathways: (i) the degradation of 3-methyl-branched fat...

Objective: To investigate the impact of fortification by comparing food records and selected biochemical indicators of nutritional status preand post-fortification. Design: Mean intake from 24 h recalls (n 142) was compared with the Estimated Average Requirement (EAR) to determine the proportion with inadequate intake. In a subsample (n 34), diet and serum retinol, folate, ferritin and Zn were ...