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Detection of MTRR 66A-->G polymorphism using the real-time polymerase chain reaction machine LightCycler for determination of composition of allele after restriction cleavage.

https://arctichealth.org/en/permalink/ahliterature79832
Source
Scand J Clin Lab Invest. 2006;66(8):685-93
Publication Type
Article
Date
2006
Author
Tvedegaard K C
Rüdiger N S
Pedersen B N
Møller J.
Author Affiliation
Institute of Public Health, NANEA at Department of Epidemiology, University of Aarhus, Aarhus, Denmark. kct1@stofanet.dk
Source
Scand J Clin Lab Invest. 2006;66(8):685-93
Date
2006
Language
English
Publication Type
Article
Keywords
Alleles
DNA Mutational Analysis
DNA Restriction Enzymes - chemistry
Denmark
Ferredoxin-NADP Reductase - genetics
Gene Frequency
Genotype
Humans
Infant, Newborn
Polymorphism, Single Nucleotide
Reverse Transcriptase Polymerase Chain Reaction - instrumentation - methods
Sensitivity and specificity
Abstract
The MTRR gene codes for methionine synthase reductase, one of the enzymes involved in the conversion of homocysteine to methionine. This conversion influences the overall level of total plasma homocysteine (tHcy) and mutations, which reduces the enzyme activity and results in an increased concentration of tHcy. A high homocysteine level is a well-documented independent risk factor for cardiovascular disease. A polymorphism in the gene for methionine synthase reductase (MTRR 66 A>G) has been shown to be associated with the risk of giving birth to a child with Down's syndrome, and the risk of having a foetus with neural tube defects. We have established a method for analysing MTRR 66A>G on DNA from dried blood spots using melting temperature analysis. The DNA was extracted from dried blood spots using a fast procedure by boiling only.
PubMed ID
17101561 View in PubMed
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Source
Appl Biochem Biotechnol. 2004;113-116:433-45
Publication Type
Article
Date
2004
Author
Carla C B Pereira
Mônica A P da Silva
Marta A P Langone
Author Affiliation
Escola de Química, Universidade Federal do Rio de Janeiro, Centro de Tecnologia, Bloco E, Lab I 221, Cidade Universitária, Brazil.
Source
Appl Biochem Biotechnol. 2004;113-116:433-45
Date
2004
Language
English
Publication Type
Article
Keywords
Biotechnology - methods
Chromatography, Gas
Enzymes - chemistry
Enzymes, Immobilized
Esters
Glycerides - biosynthesis - chemistry
Glycerol - chemistry
Laurates - chemistry
Lauric Acids - chemistry
Lipase - chemistry
Models, Theoretical
Monoglycerides
Research Support, Non-U.S. Gov't
Temperature
Time Factors
Abstract
The aim of this study was to produce monolaurin utilizing a commercial immobilized lipase (Lipozyme IM-20; Novo Nordisk, Bagsvaerd, Denmark) through the direct esterification of lauric acid and glycerol in a solvent-free system. The influence of fatty acid/glycerol molar ratio, temperature, and Lipozyme (IM-20) concentration on the molar fraction of monolaurin were determined using an experimental design. The best conditions employed were 55 degrees C, lauric acid/glycerol molar ratio of 1.0, and 3.0% (w/w) enzyme concentration. The final product, obtained after 6 h of reaction, was 45.5% monolaurin, 26.8% dilaurin, 3.1% trilaurin, and 24.6% lauric acid. The reusability of the enzyme was also studied.
PubMed ID
15054269 View in PubMed
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Evidence for key enzymatic controls on metabolism of Arctic river organic matter.

https://arctichealth.org/en/permalink/ahliterature262873
Source
Glob Chang Biol. 2014 Apr;20(4):1089-100
Publication Type
Article
Date
Apr-2014
Author
Paul J Mann
William V Sobczak
Madeleine M Larue
Ekaterina Bulygina
Anna Davydova
Jorien E Vonk
John Schade
Sergei Davydov
Nikita Zimov
Robert M Holmes
Robert G M Spencer
Source
Glob Chang Biol. 2014 Apr;20(4):1089-100
Date
Apr-2014
Language
English
Publication Type
Article
Keywords
Arctic Regions
Biological Oxygen Demand Analysis
Carbon - analysis - metabolism
Ecosystem
Enzymes - chemistry - metabolism
Glucosidases - metabolism
Monophenol Monooxygenase - chemistry - metabolism
Nitrogen - analysis
Phosphoric Monoester Hydrolases - metabolism
Polyphenols - analysis - metabolism
Rivers
Siberia
Abstract
Permafrost thaw in the Arctic driven by climate change is mobilizing ancient terrigenous organic carbon (OC) into fluvial networks. Understanding the controls on metabolism of this OC is imperative for assessing its role with respect to climate feedbacks. In this study, we examined the effect of inorganic nutrient supply and dissolved organic matter (DOM) composition on aquatic extracellular enzyme activities (EEAs) in waters draining the Kolyma River Basin (Siberia), including permafrost-derived OC. Reducing the phenolic content of the DOM pool resulted in dramatic increases in hydrolase EEAs (e.g., phosphatase activity increased >28-fold) supporting the idea that high concentrations of polyphenolic compounds in DOM (e.g., plant structural tissues) inhibit enzyme synthesis or activity, limiting OC degradation. EEAs were significantly more responsive to inorganic nutrient additions only after phenolic inhibition was experimentally removed. In controlled mixtures of modern OC and thawed permafrost endmember OC sources, respiration rates per unit dissolved OC were 1.3-1.6 times higher in waters containing ancient carbon, suggesting that permafrost-derived OC was more available for microbial mineralization. In addition, waters containing ancient permafrost-derived OC supported elevated phosphatase and glucosidase activities. Based on these combined results, we propose that both composition and nutrient availability regulate DOM metabolism in Arctic aquatic ecosystems. Our empirical findings are incorporated into a mechanistic conceptual model highlighting two key enzymatic processes in the mineralization of riverine OM: (i) the role of phenol oxidase activity in reducing inhibitory phenolic compounds and (ii) the role of phosphatase in mobilizing organic P. Permafrost-derived DOM degradation was less constrained by this initial 'phenolic-OM' inhibition; thus, informing reports of high biological availability of ancient, permafrost-derived DOM with clear ramifications for its metabolism in fluvial networks and feedbacks to climate.
PubMed ID
24115585 View in PubMed
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