myo-Inositol: Biosynthesis and Metabolism

Loewus, Frank A.; Loewus, Mary W.

doi:10.1016/b978-0-12-675403-2.50008-9

Cited by 126 publications

(152 citation statements)

References 231 publications

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“…Na + acted as a mild inhibitor of this enzyme as observed for the enzyme from other sources. Divalent cations also exhibited activities similar to those reported earlier from other sources (Wells et al, 1974;Loewus and Loewus, 1980). The strong enzyme inhibition due to heavy metals suggests that one or more free sulphydryl groups are present within the active site of the enzyme (Nelson and Cox, 2000).…”

Section: Discussionsupporting

confidence: 69%

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Myo-inositol content in pteridophytes and the isolation and characterization of L-myo-inositol-1-phosphate synthase from Diplopterygium glaucum

Chhetri¹,

Mukherjee

Adhikari

2006

Braz. J. Plant Physiol.

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Myo-inositol is involved in normal growth and development of all living organisms and L-myo-inositol-1-phosphate synthase (MIPS; EC: 5.5.1.4) is responsible for its de novo synthesis. This enzyme has been reported for a number of life forms including plants, animals and bacteria. In the present study free myo-inositol has been detected in the common pteridophytes found in the Darjeeling Himalayas and the enzyme, L-myo-inositol-1-phosphate synthase has been partially purified from Diplopterygium glaucum (Thunb.) Nakai. A crude homogenate from the reproductive pinnules of D. glaucum was subjected to streptomycin sulphate precipitation and 0-70% ammonium sulphate fractionation followed by successive chromatography through DEAEcellulose, Hexylagarose and BioGel A-0.5m columns. This resulted in a partial purification of the enzyme of about 81-fold with 13.5% recovery. The pteridophytic MIPS specifically utilized D-glucose-6-phosphte and NAD + as its substrate and co-factor, respectively. It shows a pH optimum between 7.0 and 7.5 while the temperature maximum was 30 °C. The enzyme activity was stimulated by NH 4 + , slightly inhibited by Na + , Ba 2+ and Cd 2+ , and strongly inhibited by Li + , Zn 2+ and Hg 2+ . EDTA, pCMB and some substrate isomers like glucose-1-phosphate, fructose-6-phosphte and galactose-6-phosphate were inhibitory to the enzyme. The apparent molecular weight of the native D. glaucum MIPS was determined to be approximately 171 kDa. Key words: D-glucose-6-phosphate, Gleicheniaceae, inositol synthase, myo-inositol. Conteúdo de myo-inositol em pteridófitas e o isolamento e caracterização da sintase de L-myo-inositol-1-fosfato de Diplopterygium glaucum:Myo-inositol está envolvido no crescimento e desenvolvimento de todos os organismos vivos e a enzima sintase do L-myo-inositol-1-fosfato (MIPS; EC: 5.5.1.4) é responsável pela sua síntese de novo. Esta enzima tem sido relatada em um número grande de plantas, animais e bactérias. No presente estudo myo-inositol não complexado foi detectado em pteridófitas comuns encontradas em Darjeeling Himalayas e a enzima sintase do L-myo-inositol-1-fosfato foi parcialmente purificada a partir de Diplopterygium glaucum (Thunb.) Nakai. Um extrato protéico não purificado de pinulas reprodutivas foi precipitada com sulfato de estreptomicina e 0-70% sulfato de amônia seguido de sucessivas cromatografias em colunas de DEAE-celulose, Hexylagarose e BioGel A. Este procedimento resultou na purificação parcial de 81 vezes, com recuperação de 13.5%. A MIPS dessa pteridófita usou especificamente D-glicose-6-fosfato and NAD + como substrato e cofator, respectivamente. Mostrou pH ótimo entre 7,0 e 7,5, enquanto a temperatura ótima foi 30°C. A atividade da enzima foi estimulada por NH 4 + , pouco inibida por Na + , Ba 2+ e Cd 2+ , e fortemente inibida por Li + , Zn 2+ e Hg 2+ . EDTA, pCMB e alguns substratos isôme-ros, como glicose-1-fosfato, frutose-6-fosfato e galactose-6-fosfato inibiram a enzima. A massa molecular aparente da MIPS de D. glaucum é aproximadamente 171 kDa. Palavr...

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Section: Discussionsupporting

confidence: 69%

“…Earlier studies with other plants have shown that the production of MIPS is repressed by the addition of EDTA (Loewus and Loewus, 1983).…”

Section: Effect Of Edtamentioning

confidence: 94%

Myo-inositol content in pteridophytes and the isolation and characterization of L-myo-inositol-1-phosphate synthase from Diplopterygium glaucum

Chhetri¹,

Mukherjee

Adhikari

2006

Braz. J. Plant Physiol.

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“…Although MIPP activity has been previously reported for some flowering plant species (Loewus and Loewus 1983;Gumber et al, 1984), no investigation has so far been made to look for this activity among pteridophytes. Results presented here show the existence of MIPP in a variety of vascular cryptogams.…”

Section: Discussionmentioning

confidence: 99%

“…So far, work with regard to the participation of the subsequent enzyme in this metabolic sequence, myo-inositol-1-phosphate phosphatase (MIPP), has been carried out principally in animal systems (Eisenberg Jr, 1967;Attwood et al, 1988;Gee et al, 1988;Honchar et al, 1989;Leech et al, 1993;Pollack et al, 1994;Kwok and Lo, 1994;Fujimoto et al, 1996;Caselli et al, 1996), in archaea (Wang et al, 2006), in bacteria (Nigou and Besra, 2002), and in cyanobacteria (Patra et al, 2007). However, only a few reports are available of this enzyme from plant systems (Loewus and Loewus, 1983;Gumber et al, 1984). Therefore, although the inositol biosynthetic pathway is necessarily functional in the vascular cryptogams, the supporting evidence is based only on MIPS (Chhetri et al, 2005(Chhetri et al, , 2006 without any information on MIPP.…”

Section: Introductionmentioning

confidence: 99%

Occurrence of myo-inositol-1-phosphate phosphatase in pteridophytes: characteristics of the enzyme from the reproductive pinnules of Dryopteris filix-mas (L.) Schott

Banerjee

Chhetri²,

Adhikari

2007

Braz. J. Plant Physiol.

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Evident myo-inositol-1-phosphate phosphatase (MIPP) activity has been detected both in the vegetative as well as in the spore-bearing organs of some selected pteridophytes having wide phylogenetic diversity. The basic characterization of this enzyme was carried out using the cosmopolitan fern Dryopteris filix-mas. The enzyme was partially purified from the cytosol fraction obtained from the reproductive pinnules of the plant to about 41-fold over the initial homogenate following low-speed centrifugation, streptomycin sulfate precipitation, 25-70% ammonium sulfate fractionation, CM Sephadex C-50 chromatography and finally gel-filtration on Ultrogel AcA 34. The apparent molecular weight of the native MIPP was estimated to be 94 kDa. The enzyme activity increased linearly with respect to protein concentration to about 150 µg and with respect to time up to 75 min. The temperature optimum was found at 40ºC. However, the enzyme showed good activity over the temperature range of 30-50ºC. This enzyme used D/L-myo-inositol-1-phosphate as its principal substrate (95-100%), however, about 16% activity was recorded when D-myo-inositol-3-phosphate substituted as substrate. Furthermore, weak (3%) activity of this MIPP was observed with 2-glycerophosphate as substrate. The apparent K m for pteridophytic MIPP was 0.083 mM. The enzyme was functional in a narrow pH range of 7.5 to 8.5. The activity of this MIPP enzyme was remarkably inhibited by the presence of a monovalent cation, lithium, and even moderately so at a low concentration such as 1 mM. On the other hand, magnesium, a divalent cation, enhanced activity at least up to 10 mM. Calcium diminished MIPP activity at concentrations over 4 mM. Key words: Dryopteris filix-mas, myo-inositol-1-phosphate phosphatase, pteridophytes, reproductive pinnulesOcorrência da fosfatase do mio-inositol-1-fosfato em pteridófitas: características da enzima a partir de pínulas reprodutivas de Dryopteris filix-mas (L.) Schott: Tem-se detectado atividade da fosfatase do mio-inositol-1-fosfato (FMIF) tanto em órgãos vegetativos como em estruturas esporulantes de algumas pteridófitas com ampla diversidade filogenética. Neste estudo, procedeu-se à caracterização básica dessa enzima utilizando-se da pteridófita cosmopolita Dryopteris filix-mas. Após centrifugação em baixa velocidade, precipitação com sulfato de estreptomicina, fracionamento com sulfato de amônio (25-70%), cromatografia em CM Sephadex C-50 e, finalmente, filtração gélica em Ultrogel AcA 34, conseguiu-se uma purificação parcial da enzima (a partir da fração citossólica obtida de pínulas reprodutivas da planta) de cerca de 41 vezes em relação ao homogenato inicial. O peso molecular aparente da FMIF nativa foi estimado em 94 kDa. A atividade da enzima aumentou linearmente com relação ao conteúdo de proteína (cerca de 150 µg) e com relação ao tempo (até 75 min). A temperatura ótima foi de 40ºC. Entretanto, a enzima exibiu atividade razoável na faixa de temperatura entre 30 e 50ºC. O D/L-mio-inositol-1-fosfato foi o principal substrato (9...

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“…It also catalyzes the phosphorylation of phosphatidylinositol-4,5-bisphosphate (PIP 2 ) to form phosphatidylinositol-4-phosphate (PIP) (Divecha and Irvine 1995). Glyma07g32190 is a solute carrier of Glucose-6-phosphate/phosphate which is the source of Ins before being converted to D-Ins 3-phosphate, the precursor of all remaining Ins-containing compounds (Loewus and Loewus 1983;Raboy et al 2001). Finally, there was a ZIP Zinc transporter (Glyma07g34930) in the QTL interval, which transports iron as well.…”

Section: Discussionmentioning

confidence: 99%

Evaluation and QTL mapping of phosphorus concentration in soybean seed

et al. 2012

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Phosphorus (P) is an essential macronutrient required for many biological and metabolic plant functions. Phosphate is the form of P used by plants.Reducing the amount of P in the seed can further aide breeding efforts to reduce the amount of P released into the environment due to the indigestibility of the complexes formed with metal ions. Analysis of the variation of phosphorus concentration in soybean seed under non-stressed conditions revealed that phosphorus ranged from 3,948.1 to 5,695.8 lg/g total phosphorous (TP) in combined years. The averages for independent years were significantly different from one another. Quantitative trait loci (QTL) analysis of TP was performed to identify candidate gene(s) that is (are) involved in P accumulation in soybean seed. One putative QTL region was identified on chromosome 12 in the combined data that contained a phosphate transporter gene. Two additional suggestive QTL were identified on chromosomes 7 and 17 with chromosome 7 having both a phosphate transport gene and a ZIP transporter gene in the region of the QTL. There were additional genes in these regions that are involved in phosphate metabolism and transport.

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myo-Inositol: Biosynthesis and Metabolism

Cited by 126 publications

References 231 publications

Myo-inositol content in pteridophytes and the isolation and characterization of L-myo-inositol-1-phosphate synthase from Diplopterygium glaucum

Myo-inositol content in pteridophytes and the isolation and characterization of L-myo-inositol-1-phosphate synthase from Diplopterygium glaucum

Occurrence of myo-inositol-1-phosphate phosphatase in pteridophytes: characteristics of the enzyme from the reproductive pinnules of Dryopteris filix-mas (L.) Schott

Evaluation and QTL mapping of phosphorus concentration in soybean seed

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