hexokinase

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ヘキソキナーゼ

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出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2015/09/03 04:25:17」(JST)

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英文文献

  • Development of a highly sensitive, high-throughput assay for glycosyltransferases using enzyme-coupled fluorescence detection.
  • Kumagai K1, Kojima H2, Okabe T2, Nagano T2.Author information 1Open Innovation Center for Drug Discovery, The University of Tokyo, Tokyo 113-0033, Japan; Genomic Science Laboratories, Dainippon Sumitomo Pharma Co. Ltd., Osaka 554-0022, Japan. Electronic address: kazuo-kumagai@mol.f.u-tokyo.ac.jp.2Open Innovation Center for Drug Discovery, The University of Tokyo, Tokyo 113-0033, Japan.AbstractGlycosyltransferases catalyze transfer of sugar moieties from activated donor molecules to specific acceptor molecules, forming glycosidic bonds. Identification of selective modulators of glycosyltransferases is important both to provide new tools for investigating pathophysiological roles of glycosylation reactions in cells and tissues, and as new leads in drug discovery. Here we describe a universal enzyme-coupled fluorescence assay for glycosyltransferases, based on quantification of nucleotides produced in the glycosyl transfer reaction. GDP, UDP, and CMP are phosphorylated with nucleotide kinase in the presence of excess ATP, generating ADP. Via coupled enzyme reactions involving ADP-hexokinase, glucose-6-phosphate dehydrogenase, and diaphorase, the ADP is utilized for conversion of resazurin to resorufin, which is determined by fluorescence measurement. The method was validated by comparison with an HPLC method, and employed to screen the LOPAC1280 library for inhibitors in a 384-well plate format. The assay performed well, with a Z'-factor of 0.80. We identified 12 hits for human galactosyltransferase B4GALT1 after elimination of false positives that inhibited the enzyme-coupled assay system. The assay components are all commercially available and the reagent cost is only 2 to 10 US cents per well. This method is suitable for low-cost, high-throughput assay of various glycosyltransferases and screening of glycosyltransferase modulators.
  • Analytical biochemistry.Anal Biochem.2014 Feb 15;447:146-55. doi: 10.1016/j.ab.2013.11.025. Epub 2013 Dec 1.
  • Glycosyltransferases catalyze transfer of sugar moieties from activated donor molecules to specific acceptor molecules, forming glycosidic bonds. Identification of selective modulators of glycosyltransferases is important both to provide new tools for investigating pathophysiological roles of glycos
  • PMID 24299989
  • Intraspecific variation in flight metabolic rate in the bumblebee Bombus impatiens: repeatability and functional determinants in workers and drones.
  • Darveau CA, Billardon F, Bélanger K.Author information Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, ON, K1N 6N5, Canada.AbstractThe evolution of flight energetics requires that phenotypes be variable, repeatable and heritable. We studied intraspecific variation in flight energetics in order to assess the repeatability of flight metabolic rate and wingbeat frequency, as well as the functional basis of phenotypic variation in workers and drones of the bumblebee species Bombus impatiens. We showed that flight metabolic rate and wingbeat frequency were highly repeatable in workers, even when controlling for body mass variation using residual analysis. We did not detect significant repeatability in drones, but a smaller range of variation might have prevented us from finding significant values in our sample. Based on our results and previous findings, we associated the high repeatability of flight phenotypes in workers to the functional links between body mass, thorax mass, wing size, wingbeat frequency and metabolic rate. Moreover, differences between workers and drones were as predicted from these functional associations, where drones had larger wings for their size, lower wingbeat frequency and lower flight metabolic rate. We also investigated thoracic muscle metabolic phenotypes by measuring the activity of carbohydrate metabolism enzymes, and we found positive correlations between mass-independent metabolic rate and the activity of all enzymes measured, but in workers only. When comparing workers and drones that differ in flight metabolic rate, only the activity of the enzymes hexokinase and trehalase showed the predicted differences. Overall, our study indicates that there should be correlated evolution among physiological phenotypes at multiple levels of organization and morphological traits associated with flight.
  • The Journal of experimental biology.J Exp Biol.2014 Feb 15;217(Pt 4):536-44. doi: 10.1242/jeb.091892. Epub 2013 Nov 6.
  • The evolution of flight energetics requires that phenotypes be variable, repeatable and heritable. We studied intraspecific variation in flight energetics in order to assess the repeatability of flight metabolic rate and wingbeat frequency, as well as the functional basis of phenotypic variation in
  • PMID 24198266
  • Contributions of glycogen to astrocytic energetics during brain activation.
  • Dienel GA, Cruz NF.Author information Department of Neurology, University of Arkansas for Medical Sciences, Slot 500, 4301 W. Markham St., Little Rock, AR, 72205, USA, gadienel@uams.edu.AbstractGlycogen is the major store of glucose in brain and is mainly in astrocytes. Brain glycogen levels in unstimulated, carefully-handled rats are 10-12 μmol/g, and assuming that astrocytes account for half the brain mass, astrocytic glycogen content is twice as high. Glycogen turnover is slow under basal conditions, but it is mobilized during activation. There is no net increase in incorporation of label from glucose during activation, whereas label release from pre-labeled glycogen exceeds net glycogen consumption, which increases during stronger stimuli. Because glycogen level is restored by non-oxidative metabolism, astrocytes can influence the global ratio of oxygen to glucose utilization. Compensatory increases in utilization of blood glucose during inhibition of glycogen phosphorylase are large and approximate glycogenolysis rates during sensory stimulation. In contrast, glycogenolysis rates during hypoglycemia are low due to continued glucose delivery and oxidation of endogenous substrates; rates that preserve neuronal function in the absence of glucose are also low, probably due to metabolite oxidation. Modeling studies predict that glycogenolysis maintains a high level of glucose-6-phosphate in astrocytes to maintain feedback inhibition of hexokinase, thereby diverting glucose for use by neurons. The fate of glycogen carbon in vivo is not known, but lactate efflux from brain best accounts for the major metabolic characteristics during activation of living brain. Substantial shuttling coupled with oxidation of glycogen-derived lactate is inconsistent with available evidence. Glycogen has important roles in astrocytic energetics, including glucose sparing, control of extracellular K+ level, oxidative stress management, and memory consolidation; it is a multi-functional compound.
  • Metabolic brain disease.Metab Brain Dis.2014 Feb 12. [Epub ahead of print]
  • Glycogen is the major store of glucose in brain and is mainly in astrocytes. Brain glycogen levels in unstimulated, carefully-handled rats are 10-12 μmol/g, and assuming that astrocytes account for half the brain mass, astrocytic glycogen content is twice as high. Glycogen turnover is slow under b
  • PMID 24515302

和文文献

  • Enhancement of xylose uptake in 2-deoxyglucose tolerant mutant of Saccharomyces cerevisiae(BIOCHEMICAL ENGINEERING)
  • Kahar Prihardi,Taku Kazuo,Tanaka Shuzo
  • Journal of bioscience and bioengineering 111(5), 557-563, 2011-05
  • … This was also confirmed by in vitro analyses of key enzymes involved in glucose and xylose metabolism, such as hexokinase, glucose-6-phosphate dehydrogenase and xylose reductase. … Glucose uptake was moderately suppressed in the presence of trehalose-6-phosphate inhibiting the activation of hexokinase, resulting in more uptake of xylose through hexose transport system. …
  • NAID 110008661204
  • Effect of the D-glucose analog, D-allose, on the growth of Arabidopsis roots
  • KATO NOGUCHI HISASHI,TAKAOKA TAKUYA,OKADA KOZUE
  • Weed biology and management 11(1), 7-11, 2011-03-01
  • NAID 10028178295

関連リンク

ヘキソキナーゼ(hexokinase)は、D-グルコース、D-マンノース、D-フルクトースなどの ヘキソースをリン酸化するキナーゼの一種である。ヘキソキナーゼはATPの末端のリン酸 基を一般のヘキソースのヒドロキシル基に転移させる。ヘキソキナーゼはすべての生物 ...
A hexokinase is an enzyme that phosphorylates a six-carbon sugar, a hexose, to a hexose phosphate. In most tissues and organisms, glucose is the most important substrate of hexokinases, and glucose-6-phosphate the most important  ...

関連画像

catalyzed by hexokinaseHexokinase der Backhefe . Links: offene Hexokinase, Glucokinase, EC 2.7.1.1Crystal structures of hexokinase 1 from Hexokinase Type 1 - Proteopedia, life in Hexokinase - Wikipedia, the free


★リンクテーブル★
リンク元解糖系」「グルコース6-リン酸」「代謝系」「ヘキソキナーゼ
拡張検索phosphohexokinase

解糖系」

  [★]

glycolytic pathway
エムデン-マイヤーホフ経路 Embden-Meyerhof pathway
解糖TCA回路
  • CH(OH)-CH(OH)-C(OH)H-CH(OH)-C(CH2OH)H-O- グルコース (OHが↓↓↑↓↑)
  • CH(OH)-CH(OH)-C(OH)H-CH(OH)-C(CH2O-PO3)H-O- グルコース-6-リン酸 (OHが↓↓↑↓↑)
  • C(CH2OH)OH-C(OH)H-CH(OH)-C(CH2O-PO3)H-O- フルクトース-6-リン酸
  • C(CH2O-PO3)OH-C(OH)H-CH(OH)-C(CH2O-PO3)H-O- フルクトース-1,6-リン酸
glucose
↓-hexokinase/glucokinase(liver)
glucose 6-phosphate
↓-phosphohexose isomerase
fructose 6-phosphate
↓-phosphofructokinase
fructose 1,6-bisphosphate
↓-aldolase
glyceraldehyde 3-phosphate
↓-glyceraldehyde-3-phosphate dehydrogenase
1,3-bisphosphoglycerate
↓-phosphoglycerate kinase →ATP
3-phosphoglycerate
↓-phosphoglyceate mutase
2-phosphoglycerate
↓-enolase
phosphoenolpyruvate
↓-pyruvate kinase → ATP
pyruvate
 -(pyruvate dehydrogenase)→acetyl-CoA
 -(pyruvate carboxylase)→oxaloacetate-(NADH+H+)→malate


解糖系の酵素 (first aid step1 2006 p.87, FASTEP1_87_酵素一覧.xls)

1 galactokinase キナーゼ  
2 galactose-1-phosphate uridyltransferase 転移酵素  
3 hexokinase/glucokinase キナーゼ  
4 glucose-6-phosphatase ホスファターゼ  
5 glucose-6-phosphate dehydrogenase 脱水素酵素  
6 transketolase    
7 phosphofructokinase キナーゼ  
8 fructose-1,6-bisphosphatase ホスファターゼ  
9 fructokinase キナーゼ フルクトキナーゼ
10 aldolase B   アルドラーゼ
11 pyruvate kinase キナーゼ ピルビン酸キナーゼ
12 pyruvate dehydrogenase 脱水素酵素 ピルビン酸デヒドロゲナーゼ
13 HMG-CoA reductase 還元酵素 HMG-CoA還元酵素
14 pyruvate carboxylase カルボキシラーゼ ピルビン酸カルボキシラーゼ
15 PEP carboxykinase キナーゼ PEPカルボキシキナーゼ
16 citrate synthase 合成酵素 クエン酸合成酵素
17 α-ketoglutarate dehydrogenase 脱水素酵素 α-ケトグルタミン酸脱水素酵素
18 ornithine transcarbamylase 転移酵素 オルニチンカルバモイルトランスフェラーゼ




グルコース6-リン酸」

  [★]

glucose 6-phosphate, G6P, G-6-P
グルコース-6-リン酸 glucose-6-phosphate
グルコース1-リン酸グルコース解糖系糖新生


グルコース6-リン酸の運命(G6P) (FB.451)

  1. グルコース
  2. グリコーゲン
  3. リボース5-リン酸(R5P)
  4. アセチルCoA

解糖

酵素

グリコーゲン分解

糖新生

臨床関連



代謝系」

  [★]

metabolic pathway
代謝経路
  • 解糖系
  • TCA回路
  • 電子伝達系
  • 尿酸回路
  • 糖新生経路


ヘキソキナーゼ」

  [★]

hexokinase, HK, Hx
グルコキナーゼグルコース
  • 主にで発現



phosphohexokinase」

  [★]

ホスホヘキソキナーゼ




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