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https://www.readbyqxmd.com/read/29786139/one-carbon-metabolite-ratios-as-functional-b-vitamin-markers-and-in-relation-to-colorectal-cancer-risk
#1
Björn Gylling, Robin Myte, Arve Ulvik, Per M Ueland, Øivind Midttun, Jörn Schneede, Göran Hallmans, Jenny Häggström, Ingegerd Johansson, Bethany Van Guelpen, Richard Palmqvist
One-carbon metabolism biomarkers are easily measured in plasma, but analyzing them one at a time in relation to disease does not take into account the interdependence of the many factors involved. The relative dynamics of major one-carbon metabolism branches can be assessed by relating the functional B-vitamin marker total homocysteine (tHcy) to transsulfuration (total cysteine) and methylation (creatinine) outputs. We validated the ratios of tHcy to total cysteine (Hcy:Cys), tHcy to creatinine (Hcy:Cre), and tHcy to cysteine to creatinine (Hcy:Cys:Cre) as functional markers of B-vitamin status...
May 22, 2018: International Journal of Cancer. Journal International du Cancer
https://www.readbyqxmd.com/read/29783689/cobalamin-and-folate-status-among-breastfed-infants-in-bhaktapur-nepal
#2
Ram K Chandyo, Manjeswori Ulak, Ingrid Kvestad, Mari Hysing, Merina Shrestha, Suman Ranjitkar, Arve Ulvik, Per Magne Ueland, Laxman Shrestha, Tor A Strand
Cobalamin and folate are crucial micronutrients during infancy and they are required for growth and cognitive development. Due to the monotonous and predominantly vegetarian-based complementary feeding and poor maternal micronutrient status, infants from low- and middle-income countries are susceptible to cobalamin deficiency. However, data on plasma cobalamin and folate and the functional markers methylmalonic acid and total homocysteine from breastfed infants in Nepal are still needed. We collected plasma samples from 316 6⁻11-month-old breastfed infants with a length-for-age of less than minus one z -score and analyzed blood for plasma folate, cobalamin, methylmalonic acid and total homocysteine concentrations...
May 18, 2018: Nutrients
https://www.readbyqxmd.com/read/29779954/construction-of-fluorescent-analogs-to-follow-the-uptake-and-distribution-of-cobalamin-vitamin-b-12-in-bacteria-worms-and-plants
#3
Andrew D Lawrence, Emi Nemoto-Smith, Evelyne Deery, Joseph A Baker, Susanne Schroeder, David G Brown, Jennifer M A Tullet, Mark J Howard, Ian R Brown, Alison G Smith, Helena I Boshoff, Clifton E Barry, Martin J Warren
Vitamin B12 is made by only certain prokaryotes yet is required by a number of eukaryotes such as mammals, fish, birds, worms, and Protista, including algae. There is still much to learn about how this nutrient is trafficked across the domains of life. Herein, we describe ways to make a number of different corrin analogs with fluorescent groups attached to the main tetrapyrrole-derived ring. A further range of analogs were also constructed by attaching similar fluorescent groups to the ribose ring of cobalamin, thereby generating a range of complete and incomplete corrinoids to follow uptake in bacteria, worms, and plants...
April 28, 2018: Cell Chemical Biology
https://www.readbyqxmd.com/read/29779655/cobalamin-dependent-c-methyltransferases-from-marine-microbes-accessibility-via-rhizobia-expression
#4
Michael F Freeman
Cobalamin-dependent radical S-adenosylmethionine (rSAM) methyltransferases catalyze chemically challenging methylation reactions on diverse natural products at unactivated carbon centers. In vivo reconstitution and biosynthetic studies of natural product gene clusters encoding these enzymes are often severely limited by ineffective heterologous expression hosts, including the otherwise versatile Escherichia coli. In this chapter, we describe the use of rhizobia bacteria as effective expression hosts for cobalamin-dependent rSAM C-methyltransferases...
2018: Methods in Enzymology
https://www.readbyqxmd.com/read/29773468/determination-of-vitamin-b-12-in-equine-urine-by-liquid-chromatography-inductively-coupled-plasma-mass-spectrometry
#5
Ross Wenzel, Derek Major, Karly Hesp, Philip Doble
Regulating authorities in the racing industry have restricted the administration of potentially performance enhancing cobalt salts to horses. There are severe penalties for trainers presenting horses with elevated urine cobalt concentrations, and compliance is ensured via analysis of total urinary cobalt at thresholds of 100 μg/L. When cobalt is present as part of the cobalamin molecule it is not considered performance enhancing. This paper demonstrates that a horse can excrete a significant proportion of a commercially available vitamin B12 injection in urine without metabolic modification...
May 9, 2018: Journal of Trace Elements in Medicine and Biology
https://www.readbyqxmd.com/read/29772976/effects-of-storage-conditions-and-duration-on-cobalamin-concentration-in-serum-samples-from-cats-and-dogs
#6
Jennifer Kempf, Roger H Melliger, Claudia E Reusch, Peter H Kook
OBJECTIVE To evaluate the effects of storage conditions and duration on cobalamin concentration in serum samples from dogs and cats. DESIGN Experiment. SAMPLE Serum samples from 9 client-owned cats and 9 client-owned dogs. PROCEDURES Serum harvested from freshly obtained blood samples was separated into 11 aliquots/animal. One aliquot (baseline sample) was routinely transported in light-protected tubes to the laboratory for cobalamin assay; each of the remaining aliquots was stored in a refrigerator (6°C; n = 5) or at room temperature (20°C) with exposure to daylight (5) for 24, 48, 72, 96, or 120 hours...
June 1, 2018: Journal of the American Veterinary Medical Association
https://www.readbyqxmd.com/read/29755204/cryopreservation-studies-of-an-artificial-co-culture-between-the-cobalamin-requiring-green-alga-lobomonas-rostrata-and-the-bacterium-mesorhizobium-loti
#7
Christian J A Ridley, John G Day, Alison G Smith
Algal-bacterial co-cultures, rather than cultures of algae alone, are regarded as having the potential to enhance productivity and stability in industrial algal cultivation. As with other inocula in biotechnology, to avoid loss of production strains, it is important to develop preservation methods for the long-term storage of these cultures, and one of the most commonly used approaches is cryopreservation. However, whilst there are many reports of cryopreserved xenic algal cultures, little work has been reported on the intentional preservation of both algae and beneficial bacteria in xenic cultures...
2018: Journal of Applied Phycology
https://www.readbyqxmd.com/read/29751749/engineering-a-vitamin-b-12-high-throughput-screening-system-by-riboswitch-sensor-in-sinorhizobium-meliloti
#8
Yingying Cai, Miaomiao Xia, Huina Dong, Yuan Qian, Tongcun Zhang, Beiwei Zhu, Jinchuan Wu, Dawei Zhang
BACKGROUND: As a very important coenzyme in the cell metabolism, Vitamin B12 (cobalamin, VB12 ) has been widely used in food and medicine fields. The complete biosynthesis of VB12 requires approximately 30 genes, but overexpression of these genes did not result in expected increase of VB12 production. High-yield VB12 -producing strains are usually obtained by mutagenesis treatments, thus developing an efficient screening approach is urgently needed. RESULT: By the help of engineered strains with varied capacities of VB12 production, a riboswitch library was constructed and screened, and the btuB element from Salmonella typhimurium was identified as the best regulatory device...
May 11, 2018: BMC Biotechnology
https://www.readbyqxmd.com/read/29741927/transcellular-transport-of-cobalamin-in-aortic-endothelial-cells
#9
Luciana Hannibal, Keerthana Bolisetty, Armend Axhemi, Patricia M DiBello, Edward V Quadros, Sergey Fedosov, Donald W Jacobsen
Cobalamin [Cbl (or B12 )] deficiency causes megaloblastic anemia and a variety of neuropathies. However, homeostatic mechanisms of cyanocobalamin (CNCbl) and other Cbls by vascular endothelial cells are poorly understood. Herein, we describe our investigation into whether cultured bovine aortic endothelial cells (BAECs) perform transcytosis of B12 , namely, the complex formed between serum transcobalamin and B12 , designated as holo-transcobalamin (holo-TC). We show that cultured BAECs endocytose [57 Co]-CNCbl-TC (source material) via the CD320 receptor...
May 9, 2018: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
https://www.readbyqxmd.com/read/29733595/water-mediated-carbon-oxygen-hydrogen-bonding-facilitates-adomet-recognition-in-the-reactivation-domain-of-cobalamin-dependent-methionine-synthase
#10
Robert J Fick, Mary C Clay, Lucas Vander Lee, Steve Scheiner, Hashim M Al-Hashimi, Raymond C Trievel
The C-terminal domain of cobalamin-dependent methionine synthase (MetH) has an essential role in catalyzing the reactivation of the enzyme following the oxidation of its cobalamin cofactor. This reactivation occurs through reductive methylation of the cobalamin using S-adenosylmethionine (AdoMet) as the methyl donor. Herein, we examine the molecular recognition of AdoMet by the MetH reactivation domain utilizing structural, biochemical, and computational approaches. Crystal structures of the E. coli MetH reactivation domain in complex with AdoMet, the methyl transfer product S-adenosylhomocysteine (AdoHcy), and the AdoMet analog inhibitor sinefungin illustrate that the ligands exhibit an analogous conformation within the solvent-exposed substrate binding cleft of the enzyme...
May 7, 2018: Biochemistry
https://www.readbyqxmd.com/read/29731766/expanded-newborn-screening-for-inborn-errors-of-metabolism-and-genetic-characteristics-in-a-chinese-population
#11
Kejian Guo, Xuan Zhou, Xigui Chen, Yili Wu, Chuanxin Liu, Qingsheng Kong
The incidence of inborn errors of metabolisms (IEMs) varies dramatically in different countries and regions. Expanded newborn screening for IEMs by tandem mass spectrometry (MS/MS) is an efficient approach for early diagnosis and presymptomatic treatment to prevent severe permanent sequelae and death. To determine the characteristics of IEMs and IEMs-associated mutations in newborns in Jining area, China, 48,297 healthy neonates were recruited for expanded newborn screening by MS/MS. The incidence of IEMs was 1/1178 in Jining, while methylmalonic acidemia, phenylketonuria, and primary carnitine deficiency ranked the top 3 of all detected IEMs...
2018: Frontiers in Genetics
https://www.readbyqxmd.com/read/29721769/characterization-of-the-complex-between-native-and-reduced-bovine-serum-albumin-with-aquacobalamin-and-evidence-of-dual-tetrapyrrole-binding
#12
Ilia A Dereven'kov, Luciana Hannibal, Sergei V Makarov, Anna S Makarova, Pavel A Molodtsov, Oskar I Koifman
Serum albumin binds to a variety of endogenous ligands and drugs. Human serum albumin (HSA) binds to heme via hydrophobic interactions and axial coordination of the iron center by protein residue Tyr161. Human serum albumin binds to another tetrapyrrole, cobalamin (Cbl), but the structural and functional properties of this complex are poorly understood. Herein, we investigate the reaction between aquacobalamin (H2 OCbl) and bovine serum albumin (BSA, the bovine counterpart of HSA) using Ultraviolet-Visible and fluorescent spectroscopy, and electron paramagnetic resonance...
May 2, 2018: Journal of Biological Inorganic Chemistry: JBIC
https://www.readbyqxmd.com/read/29721671/markers-of-maternal-and-neonatal-cobalamin-status-and-risk-assessment-of-neurodevelopmental-disorders-in-infants
#13
REVIEW
Umesh Kapil, Sadhana Joshi
No abstract text is available yet for this article.
May 3, 2018: Indian Journal of Pediatrics
https://www.readbyqxmd.com/read/29719071/meso-modified-cobalamins-synthesis-structure-and-properties
#14
Dorota Gryko, Aleksandra Wierzba, Aleksandra Wincenciuk, Maksymilian Karczewski, Valentine I Vullev Vullev
Vitamin B12 and its derivatives present excellent paradigms for bioinspired catalysis. The inherent challenges for derivatizing cobalamins, such as vitamin B12, in order to incorporate them in supramolecular designs and materials, limit the range of their utility and applications. Herein, we present a synthetic approach toward vitamin B12 derivatives possessing electron-donating and electron-withdrawing substituents at the meso-position (C10). Spectroscopic and cyclic-voltammetry studies reveal that changes in the substitution pattern on the equatorial ligand have a significant impact on the electronic and optical properties of the cobalamin...
May 2, 2018: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29682906/profiles-of-streptococcus-thermophilus-mn-zlw-002-nutrient-requirements-in-controlled-ph-batch-fermentations
#15
Gefei Liu, Yali Qiao, Yanjiao Zhang, Cong Leng, Jiahui Sun, Hongyu Chen, Yan Zhang, Aili Li, Zhen Feng
This study aimed to evaluate the profiles of Streptococcus thermophilus nutrient requirements to guide the design of media for high cell density culturing. The growth kinetics, physiological state, and nutrient requirement profiles of S. thermophilus were analyzed in chemically defined media. The results showed that the intracellular ATP concentration, H+ -ATPase activity, NADH/NAD+ , and NH3 concentrations varied with intracellular pH. The nutrient components with the highest amounts required were Leu and Asp; ascorbic acid and p-amino benzoic acid; K+ and PO4 3- ; and guanine and uracil...
April 22, 2018: MicrobiologyOpen
https://www.readbyqxmd.com/read/29669618/determination-of-cobalamin-and-related-compounds-in-foods
#16
Fumio Watanabe, Tomohiro Bito
Cobalamin, also known as the red-colored vitamin B12 , is found in animal-based foods such as meat, milk, and fish. Various cobalamin compounds are extracted from foods and converted into cyanocobalamin, which is most stable, to be analyzed by various methods. Traditionally, the cobalamin content of foods is determined by microbiological assay with Lactobacillus delbrueckii subsp. lactis American Type Culture Collection 7830. However, this lactic acid bacterium can substitute deoxyribosides or deoxynucleotides (known as an alkali-resistant factor) for cobalamin...
April 18, 2018: Journal of AOAC International
https://www.readbyqxmd.com/read/29667183/effect-of-enterococcus-faecium-sf68-on-serum-cobalamin-and-folate-concentrations-in-healthy-dogs
#17
R Lucena, A B Olmedilla, B Blanco, M Novales, P J Ginel
OBJECTIVE: To study the effect of a 14-day administration of the probiotic Enterococcus faecium SF68 on serum concentrations of cobalamin and folate in healthy dogs. MATERIALS AND METHODS: Thirty-six healthy dogs were randomly allocated between probiotic and control groups. Enterococcus faecium SF68 was administered to the probiotic group for 14 days whereas the control group did not receive any product. A blood sample was taken from all dogs when starting the administration (day 1), when the administration ended (day 14) and 14 days later (day 28)...
April 17, 2018: Journal of Small Animal Practice
https://www.readbyqxmd.com/read/29663633/transcobalamin-receptor-defect-identification-of-two-new-cases-through-positive-newborn-screening-for-propionic-methylmalonic-aciduria-and-long-term-outcome
#18
Fady Hannah-Shmouni, Vivian Cruz, Andreas Schulze, Saadet Mercimek-Andrews
Likely pathogenic variants in CD320 cause transcobalamin receptor defect, a recently discovered inborn errors of cobalamin metabolism. Only 12 cases have been reported to date. There are no long-term clinical and biochemical outcome reports since its first description. In this report, we present two new cases and report their long-term treatment outcome. Two asymptomatic cases were identified through a positive newborn screening for propionic/methylmalonic aciduria. Biochemical abnormalities were normalized on a short course of oral cyanocobalamin (1 mg/day)...
April 16, 2018: American Journal of Medical Genetics. Part A
https://www.readbyqxmd.com/read/29651724/serum-folate-and-cobalamin-levels-and-urinary-dimethylarsinic-acid-in-us-children-and-adults
#19
Jianmin Zhu, Yanhui Gao, Dianjun Sun, Yudan Wei
Nutritional status could affect arsenic metabolism and toxicity in the general population chronically exposed to low levels of inorganic arsenic. In this study, we examined the association of serum folate and cobalamin with urinary concentrations of dimethylarsinic acid (DMA), the most abundant metabolite of inorganic arsenic measured in urine, in children and adults who participated in the 2003-2006 US National Health and Nutrition Examination Surveys. A total of 1161 children (aged 6-19 years) and 1938 adults (aged 20-85 years) were analyzed for the association using multivariate general linear models, adjusting for potential confounders...
April 12, 2018: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/29627730/determination-of-cobalt-species-in-nutritional-supplements-using-icp-oes-after-microwave-assisted-extraction-and-solid-phase-extraction
#20
Magdalena Bartosiak, Krzysztof Jankowski, Jacek Giersz
Cobalt content (as vitamin B12 and inorganic cobalt) in two nutritional supplements, namely Spirulina platensis and Saccharomyces cerevisiae known as a "superfood", has been determined using inductively coupled plasma optical emission spectrometry (ICP-OES). Several sample pre-treatment protocols have been applied and compared. Microwave-assisted acid digestion efficiently decomposed all cobalt-containing compounds, thus allowed obtaining total cobalt content in supplements examined. Vitamin B12 was extracted from the samples with acetate buffer and potassium cyanide solution exposed to mild microwave radiation for 30 min, and cyanocobalamin was separated from the extract by on-column solid phase extraction using C-18 modified silica bed...
March 31, 2018: Journal of Pharmaceutical and Biomedical Analysis
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