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1.
iScience ; 27(1): 108730, 2024 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-38235326

RESUMEN

Cirrhosis is becoming one of the most common diseases worldwide. Abnormal upregulation of transforming growth factor ß (TGF-ß) signaling plays a pivotal role in the excess activation of hepatic stellate cells. However, an efficient countermeasure against abnormal hepatic stellate cell activation is yet to be established because TGF-ß signaling is involved in several biological processes. Herein, we demonstrated the antifibrotic effect of miR-12135, a microRNA with unknown function upregulated by isoflavone. Comprehensive transcriptome assay demonstrated that miR-12135 suppressed Integrin Subunit Alpha 11 (ITGA11) and that ITGA11 expression is correlated with alpha smooth muscle actin expression in patients with cirrhosis. miR-12135 suppressed the expression level of ITGA11 and liver fibrosis. Importantly, ITGA11 is overexpressed in activated hepatic stellate cells, whereas ITGA11 knockout mice are viable and fertile. In conclusions, the miR-12135/ITGA11 axis can be an ideal therapeutic target to suppress fibrosis by precisely targeting abnormally upregulated TGF-ß signaling in hepatic stellate cells.

2.
Biosci Microbiota Food Health ; 42(1): 87-93, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36660602

RESUMEN

Quercetin, a flavonol present in many vegetables and fruits, has been identified as a chemoprevention agent in several cancer models. However, the molecular mechanism of quercetin's anticancer activity is not entirely understood. MicroRNAs (miRNAs), small noncoding RNAs, have been reported to play key roles in various biological processes by regulating their target genes. We hypothesized that quercetin can exert an anticancer effect through the regulation of miRNAs. To test this hypothesis, we investigated the effects of quercetin on the expression of tumor-suppressive miRNAs in cervical cancer. Quercetin up-regulated the in vivo and in vitro expression of tumor-suppressive miRNAs miR-26b, miR-126, and miR-320a. Quercetin suppressed the level of ß-catenin, encoded by catenin beta 1 (CTNNB1), by up-regulating miR-320a in HeLa cells. Moreover, quercetin increased the expression of mir-26b, mir-126, and mir-320a precursors in HeLa cells. The results from this study show that quercetin has the potential to prevent cervical cancer by regulating the expression of tumor-suppressive miRNAs.

3.
J Nutr Sci Vitaminol (Tokyo) ; 58(6): 438-41, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23419403

RESUMEN

This study determined the vitamin B12 content of six wild edible mushrooms which are consumed by European vegetarians. Zero or trace levels (0.01-0.09 µg/100 g dry weight) of vitamin B12 were determined in porcini mushrooms (Boletus spp.), parasol mushrooms (Macrolepiota procera), oyster mushrooms (Pleurotus ostreatus), and black morels (Morchella conica). By contrast, black trumpet (Craterellus cornucopioides) and golden chanterelle (Cantharellus cibarius) mushrooms contained considerable levels (1.09-2.65 µg/100 g dry weight) of vitamin B12. To determine whether C. cornucopioides or C. cibarius contained vitamin B12 or other corrinoid compounds that are inactive in humans, we purified a corrinoid compound using an immunoaffinity column and identified it as vitamin B12 based on LC/ESI-MS/MS chromatograms.


Asunto(s)
Agaricales/química , Vitamina B 12/análisis , Agaricales/clasificación , Cromatografía Liquida , Espectrometría de Masas en Tándem
4.
FEBS Lett ; 584(14): 3223-6, 2010 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-20558164

RESUMEN

To clarify the physiological function of pseudovitamin B(12) (or adeninylcobamide; AdeCba) in Spirulina platensis NIES-39, cobalamin-dependent methionine synthase (MS) was characterized. We cloned the full-length Spirulina MS. The clone contained an open reading frame encoding a protein of 1183 amino acids with a molecular mass of 132 kDa. Deduced amino acid sequences of the Spirulina MS contained critical residues identical to cobalamin-, zinc-, S-adenosylmethionine-, and homocysteine-binding motifs. The recombinant Spirulina enzyme showed higher affinity for methyladeninylcobamide than methylcobalamin as a cofactor. These results indicate that Spirulina cells can utilize AdeCba synthesized as the cofactor for MS.


Asunto(s)
5-Metiltetrahidrofolato-Homocisteína S-Metiltransferasa/metabolismo , Cianobacterias/metabolismo , 5-Metiltetrahidrofolato-Homocisteína S-Metiltransferasa/química , 5-Metiltetrahidrofolato-Homocisteína S-Metiltransferasa/genética , Secuencia de Aminoácidos , Bacterias/genética , Bacterias/metabolismo , Cianobacterias/genética , Compuestos Inorgánicos , Datos de Secuencia Molecular , Compuestos Orgánicos , Estructura Terciaria de Proteína/genética , S-Adenosilmetionina/genética , S-Adenosilmetionina/metabolismo , Vitamina B 12/análogos & derivados , Vitamina B 12/genética , Vitamina B 12/metabolismo
5.
Arch Microbiol ; 192(6): 437-46, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20379701

RESUMEN

Significant accumulation of the methylmalonyl-CoA mutase apoenzyme was observed in the photosynthetic flagellate Euglena gracilis Z at the end of the logarithmic growth phase. The apoenzyme was converted to a holoenzyme by incubation for 4 h at 4 degrees C with 10 microM 5'-deoxyadenosylcobalamin, and then, the holoenzyme was purified to homogeneity and characterized. The apparent molecular mass of the enzyme was calculated to be 149.0 kDa +/- 5.0 kDa using Superdex 200 gel filtration. SDS-polyacrylamide gel electrophoresis of the purified enzyme yielded a single protein band with an apparent molecular mass of 75.0 kDa +/- 3.0 kDa, indicating that the Euglena enzyme is composed of two identical subunits. The purified enzyme contained one mole of prosthetic 5'-deoxyadenosylcobalamin per mole of the enzyme subunit. Moreover, we cloned the full-length cDNA of the Euglena enzyme. The cDNA clone contained an open reading frame encoding a protein of 717 amino acids with a calculated molecular mass of 78.3 kDa, preceded by a putative mitochondrial targeting signal consisting of nine amino acid residues. Furthermore, we studied some properties and physiological function of the Euglena enzyme.


Asunto(s)
Euglena gracilis/enzimología , Metilmalonil-CoA Mutasa/química , Metilmalonil-CoA Mutasa/metabolismo , Propionatos/metabolismo , Secuencia de Aminoácidos , Aminoácidos/análisis , Apoenzimas/metabolismo , Cromatografía en Gel , Clonación Molecular , Cobamidas/metabolismo , ADN Complementario , Electroforesis en Gel de Poliacrilamida , Euglena gracilis/crecimiento & desarrollo , Euglena gracilis/metabolismo , Holoenzimas/química , Holoenzimas/genética , Holoenzimas/aislamiento & purificación , Holoenzimas/metabolismo , Cinética , Metilmalonil-CoA Mutasa/genética , Metilmalonil-CoA Mutasa/aislamiento & purificación , Mitocondrias/enzimología , Datos de Secuencia Molecular , Peso Molecular , Subunidades de Proteína/química , Proteínas Protozoarias/química , Proteínas Protozoarias/genética , Proteínas Protozoarias/aislamiento & purificación , Proteínas Protozoarias/metabolismo , Temperatura
6.
J Agric Food Chem ; 57(7): 2793-6, 2009 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-19256490

RESUMEN

Vitamin B(12) contents of various Korean purple laver products were determined with the microbiological vitamin B(12) assay method. Although a substantial amount (133.8 microg/100 g) of vitamin B(12) was found in dried purple laver, seasoned and toasted laver products contained lesser vitamin B(12) contents (about 51.7 microg/100 g). The decreased vitamin B(12) contents in the seasoned and toasted laver products, however, were not due to loss or destruction of vitamin B(12) during the toasting process. Silica gel 60 thin layer chromatography-bioautogram analysis indicated that all Korean laver products tested contain true vitamin B(12), but not inactive corrinoid compounds. In vitro gastrointestinal digestion experiments indicated that digestion rate of vitamin B(12) from the dried Korean purple laver was estimated to be 50% under pH 2.0 conditions (as a model of normal gastric function). These results suggest that Korean purple laver products would be excellent vitamin B(12) sources for humans, especially vegetarians.


Asunto(s)
Porphyra/química , Vitamina B 12/análisis , Disponibilidad Biológica , Cromatografía en Capa Delgada , Desecación , Digestión , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Manipulación de Alimentos/métodos , Calor , Técnicas In Vitro , Corea (Geográfico) , Pepsina A/metabolismo , Vitamina B 12/farmacocinética , Vitamina B 12/farmacología
7.
J Nutr Sci Vitaminol (Tokyo) ; 53(2): 183-6, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17616007

RESUMEN

Vitamin B12 content (98.8 +/- 5.6 microg/100 g dry weight) of an edible cyanobacterium, Nostoc commune (Ishikurage) was determined by the Lactobacillus delbrueckii ATCC 7830 microbiological method. Bioautography with vitamin B12-dependent Escherichia coli 215 indicated that N. commune contained two (main and minor) corrinoid-compounds. These corrinoid-compounds were purified to homogeneity from the dried algal cells and characterized. The main and minor purified corrinoid-compounds were identified as pseudovitamin B12 and vitamin B12, respectively, on the basis of silica gel 60 TLC, C18 reversed-phase HPLC, 1H NMR spectroscopy, and UV-visible spectroscopy. These results suggest that the bacterial cells are not suitable for use as a vitamin B12 source, especially in vegetarians.


Asunto(s)
Corrinoides/química , Corrinoides/aislamiento & purificación , Nostoc commune/química , Disponibilidad Biológica , Cromatografía Líquida de Alta Presión/métodos , Espectroscopía de Resonancia Magnética/métodos , Análisis Espectral/métodos , Vitamina B 12/análisis
8.
Biosci Biotechnol Biochem ; 71(1): 222-5, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17213643

RESUMEN

Newly isolated thraustochytrids showed uptake of vitamin B12 from the culture into the cells. Cultivation of thraustochytrids in a medium containing 1 microg/ml of vitamin B12 greatly increased the contents of vitamin B12 in the cells. Similarly to Schizochytrium limacinum, odd numbered fatty acids decreased in the cells of new isolates cultivated with vitamin B12. Vitamin B12-enriched thraustochytrids, strain mh0186, enhanced the population growth of rotifers fed on the cells as sole feed.


Asunto(s)
Células Eucariotas/efectos de los fármacos , Células Eucariotas/fisiología , Vitamina B 12/farmacología , Animales , Línea Celular , Proliferación Celular/efectos de los fármacos , Células Eucariotas/citología , Ácidos Grasos/metabolismo
9.
J Nutr Sci Vitaminol (Tokyo) ; 53(6): 471-5, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18202533

RESUMEN

A marine eukaryotic microorganism, Schizochytrium limacinum SR21, had the ability to absorb and accumulate exogenous cobalamin, which was converted to the cobalamin coenzymes 5'-deoxyadenosylcobalamin (20.1%) and methylcobalamin (29.6%). A considerably high activity (about 38 mU/mg protein) of 5'-deoxyadenosylcobalamin-dependent methylmalonyl-CoA mutase (EC 5.4.99.2) involved in amino acid and odd-chain fatty acid metabolism was found in the cell homogenate of S. limacinum SR21. The enzyme was purified to homogeneity and characterized.


Asunto(s)
Cobamidas/metabolismo , Coenzimas/metabolismo , Eucariontes/enzimología , Metilmalonil-CoA Mutasa/metabolismo , Animales , Cobamidas/química , Cobamidas/aislamiento & purificación , Coenzimas/química , Coenzimas/aislamiento & purificación , Activación Enzimática , Ácidos Grasos/metabolismo , Metilmalonil-CoA Mutasa/química , Metilmalonil-CoA Mutasa/aislamiento & purificación , Peso Molecular , Temperatura
10.
J Agric Food Chem ; 54(25): 9604-7, 2006 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-17147452

RESUMEN

The vitamin B12 concentration of the dried cells of Aphanizomenon flos-aquae was determined by both microbiological method with Lactobacillus delbrueckeii ATCC7830 and chemiluminescence method with intrinsic factor. The Aphanizomenon cells contained 616.3 +/- 30.3 micro g (n = 4) of vitamin B12 per 100 g of the dried cells by the microbiological method. The values determined with the chemiluminescence method, however, were only about 5.3% of the values determined by the microbiological method. A corrinoid-compound was purified from the dried cells and characterized. The purified corrinoid-compound was identified as pseudovitamin B12 (an inactive corrinoid-compound for humans) by silica gel 60 TLC, C18 reversed-phase HPLC, ultraviolet-visible spectroscopy, and 1H NMR spectroscopy. The results suggest that the Aphanizomenon cells are not suitable for use as a vitamin B12 source, especially in vegans.


Asunto(s)
Aphanizomenon/química , Corrinoides/aislamiento & purificación , Suplementos Dietéticos , Cromatografía Líquida de Alta Presión , Espectroscopía de Resonancia Magnética , Vitamina B 12/análisis
11.
Biosci Biotechnol Biochem ; 70(12): 3066-8, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17151457

RESUMEN

The edible blue-green alga (cyanobacterium), Suizenji-nori, contained 143.8+/-22.4 microg of vitamin B(12) per 100 g dry weight of the alga (mean+/-SE, n=4). A corrinoid compound was purified from the dried Suizenji-nori, and partially characterized. The silica gel 60 TLC and reversed-phase HPLC patterns of the purified corrinoid compound were not identical to those of true vitamin B(12), but to those of pseudovitamin B(12) which is inactive for humans.


Asunto(s)
Corrinoides/química , Cianobacterias/química , Cromatografía Líquida de Alta Presión , Cromatografía en Capa Delgada
12.
Yakugaku Zasshi ; 126(10): 1003-10, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17016030

RESUMEN

At the Municipal Ikeda Hospital, a system in which pharmacists stationed in one ward pharmacy dispense drugs to be administered by injection and injectable preparations delivered to patients' bedsides was introduced in April 2000. This system was aimed at minimizing risks related to injections. Initially, however, on holidays, nurses played the roles of pharmacists in terms of the injections, and there were concerns over a possible rise in the incidence of errors (adverse events/near-misses) related to injections on these days compared with weekdays. Later, when planning to introduce a new holiday work system in the ward pharmacy, we took into account such factors as the number of pharmacists needed on holidays, their duties on holidays and the influence on weekday pharmacy activity of compensatory days-off taken by such pharmacists. In May 2004, the new holiday work system was introduced in the ward pharmacy. Under the new system, 5 pharmacists work at the ward pharmacy on holidays. After this system was put into operation, the number of injections dispensed at the ward pharmacy averaged 230 per day, and 177 per holiday. To evaluate the validity of this system, we recently conducted a questionnaire survey of nurses at our hospital. The survey involved 139 nurses. Of these nurses, 69.1% responded that the number of incidents (adverse events/near-misses) related to dispensing injections on holidays had decreased. Furthermore, 65.4% of the nurses reported a decrease in incidents related to the delivery and administration of injectable preparations. More than half of the nurses answered that the new system had made it easier for them to collect information on medicines and helped them provide better nursing services. When the nurses were asked to make a general assessment of the new system, 90% rated the system as "good." The results of this survey indicate that keeping the ward pharmacy open on holidays contributes to the promotion of the proper use of medicines, reduction of risks related to injections and improvement in the quality of medical care.


Asunto(s)
Errores de Medicación/prevención & control , Sistemas de Medicación en Hospital , Farmacéuticos , Servicio de Farmacia en Hospital , Tolerancia al Trabajo Programado , Humanos , Inyecciones , Japón , Enfermeras y Enfermeros , Calidad de la Atención de Salud , Gestión de Riesgos , Encuestas y Cuestionarios
13.
J Nutr Sci Vitaminol (Tokyo) ; 51(5): 319-28, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16392702

RESUMEN

We investigated the levels of water-soluble vitamins except for vitamin B6 in the blood and urine of Japanese college male (n = 10) and female (n = 10) students. They consumed for 7 d a semi-purified diet based on Japanese Dietary Reference Intakes to assess the Recommended Dietary Allowances (RDA) for water-soluble vitamins and to present some new normal values for blood and urine levels of water-soluble vitamins in Japanese. The blood and the 24-h urine samples were collected on the last day of the experiment and measured. The values of total vitamin B1 in whole blood, total vitamin B2 in whole blood, total cyanocobalamin in serum, total nicotinamide in whole blood, total pantothenic acid in whole blood, total folates in serum, total biotin in serum, and ascorbic acid in plasma were 104+/-17 pmol/mL (mean+/-SD), 216+/-25 pmol/mL, 0.34+/-0.05 pmol/mL, 59.1+/- 5.0 nmol/ mL, 2.45+/-0.37 nmol/mL, 15.6+/-4.6 pmol/mL, 8.3+/-0.5 pmol/mL, and 62+/-10 nmol/mL, respectively, in males, and 90+/-23, 234+/-18, 0.67+/-0.20, 61.9+/-6.0, 2.48+/-0.30, 30.2+/-8.6, 8.4+/-0.3, and 67+/-14, respectively, in females. There was a significant difference in the values of cyanocobalamin and total folates between men and women. The urinary excretion of vitamin B1, vitamin B2, cyanocobalamin, sum of the catabolic metabolites of nicotinamide, pantothenic acid, folates, biotin, and ascorbic acid were 665+/-114 nmol/d, 562+/-325 nmol/d, 93+/-31 pmol/d, 84+/-26 micromol/d, 9.3+/-2.3 micromol/d, 19.4+/-2.8 nmol/d, 83+/-18 pmol/d, and 148+/-51 micromol/d, respectively, in males, and 495+/-212, 580+/-146, 145+/-49, 83+/-19, 16.9+/-1.3, 22.7+/-2.7, 83+/-23, and 140+/-51, respectively, in females. There was a significant difference in the urinary excretion of cyanocobalamin, pantothenic acid and total folates between men and women. These values will be useful for the nutritional assessment of water-soluble vitamins for Japanese, although the examination period was short. In future, an experiment with various age groups and re-evaluation by repeated experiments will provide more accurate values.


Asunto(s)
Dieta/normas , Política Nutricional , Vitaminas/sangre , Vitaminas/orina , Adulto , Regulación del Apetito , Ácido Ascórbico/sangre , Ácido Ascórbico/orina , Biotina/sangre , Biotina/orina , Femenino , Ácido Fólico/sangre , Ácido Fólico/orina , Humanos , Japón , Masculino , Niacinamida/sangre , Niacinamida/orina , Ácido Pantoténico/sangre , Ácido Pantoténico/orina , Riboflavina/sangre , Riboflavina/orina , Caracteres Sexuales , Tiamina/sangre , Tiamina/orina , Vitamina B 12/sangre , Vitamina B 12/orina
14.
Artículo en Inglés | MEDLINE | ID: mdl-15193271

RESUMEN

Low activity (about 4 mU/mg protein) of 5'-deoxyadenosylcobalamin-dependent methylmalonyl-CoA mutase (MCM; EC 5.4.99.2) was found in a cell homogenate of a photosynthetic coccolithophorid alga, Pleurochrysis carterae. Most of the enzyme occurred as the apo-enzyme, which was labile during purification. The holo-enzyme, which was converted from the apo-enzyme by incubation with 10 microM 5'-deoxyadenosylcobalamin at 4 degrees C in the dark, was purified to homogeneity and partially characterized. An apparent molecular mass for the enzyme of 150+/-5 kDa was calculated by Superdex 200 pg gel filtration. SDS-polyacrylamide gel electrophoresis of the purified enzyme gave a single protein band with an apparent molecular mass of 80+/-5 kDa, indicating that the P. carterae enzyme occurs as a homodimer. Some properties of methylmalonyl-CoA mutase from P. carterae were studied.


Asunto(s)
Eucariontes/enzimología , Metilmalonil-CoA Mutasa/aislamiento & purificación , Metilmalonil-CoA Mutasa/metabolismo , Bioquímica/métodos , Cobamidas/metabolismo , Electroforesis en Gel de Poliacrilamida , Eucariontes/fisiología , Peso Molecular , Fotosíntesis , Temperatura
15.
Arch Microbiol ; 180(2): 151-4, 2003 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12844209

RESUMEN

High activity (>60 munit/mg protein) of 5'-deoxyadenosylcobalamin-dependent methylmalonyl-CoA mutase (EC 5.4.99.2) was constantly found during growth of a strain of the root-nodule-forming bacterium Sinorhizobium meliloti harboring an extra plasmid-encoded copy of the methylmalonyl-CoA-mutase-encoding bhbA gene. The enzyme was purified to homogeneity and characterized. The purified enzyme was found to be a colorless apo-form. The apparent molecular weight of the enzyme was calculated to be 165,000+/-5,000 by Superdex 200 HR gel filtration. SDS-PAGE of the purified enzyme resolved one protein band with an apparent molecular mass of 80.0+/-2.0 kDa, indicating that the S. meliloti enzyme is composed of two identical subunits. The NH(2)-terminal sequence was identical to that predicted from the bhbA nucleotide sequence. Monovalent cations were required for enzyme activity.


Asunto(s)
Metilmalonil-CoA Mutasa/química , Metilmalonil-CoA Mutasa/aislamiento & purificación , Sinorhizobium meliloti/enzimología , Apoenzimas/aislamiento & purificación , Cromatografía en Gel , Cobamidas , Dimerización , Electroforesis en Gel de Poliacrilamida , Activación Enzimática , Holoenzimas/metabolismo , Cinética , Metilmalonil-CoA Mutasa/biosíntesis , Metilmalonil-CoA Mutasa/metabolismo , Peso Molecular , Subunidades de Proteína , Sinorhizobium meliloti/crecimiento & desarrollo
16.
J Nutr Sci Vitaminol (Tokyo) ; 48(3): 242-6, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12350084

RESUMEN

High activity (about 50 mU x mg protein(-1)) of methylmalonyl-CoA mutase (82-95% apo-enzyme) was constantly found during the cell growth of a methanol-utilizing bacterium, Methylobacterium extorquens NR-1. The apo-enzyme was purified to homogeneity and characterized. The purified enzyme was colorless. An apparent Mr of M. extorquens NR-1 enzyme was calculated to be 150,000 +/- 5,000 by Superdex 200 HR gel filtration. SDS-polyacrylamide gel electrophoresis of the purified enzyme gave two protein bands with an apparent Mr of 85.000 +/- 2,000 and 70,000 +/- 2,000, indicating that the M. extorquens NR-1 enzyme is composed of two nonidentical subunits. NH2-terminal amino acid sequences of the small and large subunits of M. extorquens NR-1 enzyme showed no significant homology to those of the enzyme from other species. Some enzymological properties of the M. extorquens NR-1 enzyme were studied.


Asunto(s)
Metilmalonil-CoA Mutasa/aislamiento & purificación , Methylobacterium extorquens/enzimología , Secuencia de Aminoácidos , Aminoácidos/análisis , Aminoácidos/química , Cromatografía en Gel , Electroforesis en Gel de Poliacrilamida , Isomerasas/aislamiento & purificación , Isomerasas/metabolismo , Metanol , Metilmalonil-CoA Mutasa/química , Metilmalonil-CoA Mutasa/metabolismo , Peso Molecular , Homología de Secuencia de Aminoácido , Especificidad de la Especie
17.
Biosci Biotechnol Biochem ; 66(1): 195-8, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11866107

RESUMEN

The photosynthetic coccolithophoid alga, Pleurochrysis (Hymenomonas) carterae, could take up and accumulate exogenous vitamin B12, most of which was converted into the coenzyme forms of vitamin B12. Two vitamin B12-dependent enzyme activities (methylmalonyl-CoA mutase, 2.6+/-0.4 nmol/min/mg protein and methionine synthase, 85.1+/-38.9 pmol/min/mg protein) could be found in a cell homogenate of the vitamin B12-supplemented alga. Most of the methylmalonyl-CoA mutase activity and 19.2% of the vitamin B12 accumulated by the algal cells were recovered in the macromolecular fractions with Mr of 150 kDa, although the remaining vitamin B12 was found only in free vitamin B12 fractions.


Asunto(s)
Eucariontes/metabolismo , Vitamina B 12/fisiología , 5-Metiltetrahidrofolato-Homocisteína S-Metiltransferasa/metabolismo , Cobamidas/metabolismo , Metilmalonil-CoA Mutasa/metabolismo , Fotosíntesis , Vitamina B 12/aislamiento & purificación , Vitamina B 12/metabolismo
18.
J Nutr Sci Vitaminol (Tokyo) ; 48(5): 325-31, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12656203

RESUMEN

Substantial amounts of vitamin B12 were found in some edible algae (green and purple lavers) and algal health food (chlorella and spirulina tablets) using the Lactobacillus delbrueckii subsp. lactis ATCC7830 microbiological assay method. Corrinoid-compounds were purified and characterized from these algae to clarify the chemical properties and bioavailability of the algal vitamin B12. True vitamin B12 is the predominate cobamide of green and purple lavers and chlorella tablets. Feeding the purple laver to vitamin B12-deficient rats significantly improved the vitamin B12 status. The results suggest that algal vitamin B12 is a bioavailable source for mammals. Pseudovitamin B12 (an inactive corrinoid) predominated in the spirulina tablets, which are not suitable for use as a vitamin B12 source, especially for vegetarians. algal health food, bioavailability, cobalamin, edible algae, vitamin B12


Asunto(s)
Eucariontes/metabolismo , Deficiencia de Vitamina B 12/dietoterapia , Vitamina B 12/aislamiento & purificación , Vitamina B 12/farmacocinética , Animales , Disponibilidad Biológica , Humanos , Ratas
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