Metabolism of vitamin

Alcohol dehydrogenase (ADH) deficiency results in decreased retinol utilization, but it is unclear what physio-logical roles the several known ADHs play in retinoid signaling. Here, Adh1, Adh3,andAdh4null mutant mice have been examined following acute and chronic vitamin A excess. Following an acute dose of retinol (50 mgÆkg )1 ), metabolism of retinol to retinoic acid in liver was reduced 10-fold inAdh1mutants and 3.8-fold inAdh3mutants, but was not significantly reduced inAdh4mutants.

6p research12 29-04-2013 52 3   Download

We show that cytochrome P450scc (CYP11A1) in either a reconstituted system or in isolated adrenal mitochondria can metabolize vita-min D3. The major products of the reaction with reconstituted enzyme were 20-hydroxycholecalciferol and 20,22-dihydroxycholecalciferol, with yields of 16 and 4%, respectively, of the original vitamin D3 substrate. Tri-hydroxycholecalciferol was a minor product, likely arising from further metabolism of dihydroxycholecalciferol.

11p fptmusic 11-04-2013 42 2   Download

We report an alternative, hydroxylating pathway for the metabolism of vitamin D2 in a cytochrome P450 side chain cleavage (P450scc; CYP11A1) reconstituted system. NMR analyses identified solely 20-hydroxyvitamin D2and 17,20-dihydroxyvitamin D2derivatives. 20-Hydroxyvitamin D2was produced at a rate of 0.34 molÆmin )1 Æmol )1 P450scc, and 17,20-dihydroxy-vitamin D2 was produced at a rate of 0.13 molÆmin )1 Æmol )1 .

11p inspiron33 25-03-2013 32 4   Download

Whether dimerization is a general regulatory mechanism of receptor protein-tyrosine phosphatases (RPTPs) is a subject of debate. Biochemical evidence demonstrates that RPTPaand cluster of differentiation (CD)45 dimerize.

12p media19 06-03-2013 44 3   Download

Cytochrome P450scc (CYP11A1) can hydroxylate vitamin D3 to produce 20-hydroxyvitamin D3 and other poorly characterized hydroxylated prod-ucts. The present study aimed to identify all the products of vitamin D3 metabolism by P450scc, as well as the pathways leading to their formation.

13p media19 06-03-2013 36 2   Download

The metabolic pathways leading froml-[2-13 C]aspartic acid, [2-13 C]glycine andl-[methyl-13 C]methionine to vitamin B12were investigated, focusing on the biosynthetic pathways leading to the aminopropanol moiety of vita-min B12and on the role of the Shemin pathway leading tod-aminolevulinic acid (a biosynthetic intermediate of tetrapyrrole), by means of feeding experiments with Propionibacterium shermaniiin combination with 13 C-NMR spectroscopy.

6p media19 04-03-2013 33 1   Download

Prokaryotes, yeasts and plants synthesize thiamin (vitamin B1) via complex pathways. Animal cells capture the vitamin through specific high-affinity transporters essential for internal thiamin homeostasis. Inside the cells, thi-amin is phosphorylated to higher phosphate derivatives. Thiamin diphos-phate (ThDP) is the best-known thiamin compound because of its role as an enzymatic cofactor.

9p viettel02 22-02-2013 32 3   Download

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học 'Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài: Asthma families show transmission disequilibrium of gene variants in the vitamin D metabolism and signalling pathway...

11p toshiba13 21-10-2011 47 3   Download

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành y đề tài: Hormone replacement therapy, calcium and vitamin D3 versus calcium and vitamin D3 alone decreases markers of cartilage and bone metabolism in rheumatoid arthritis: a randomized controlled trial [ISRCTN46523456]...

12p thulanh11 11-10-2011 40 2   Download