Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.3.8 (phytase)
1,997 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A sugar phosphomonoester, myo-inositol hexakisphosphate (phytic acid), has been identified as a major phosphorylated metabolite in Dictyostelium discoideum amoeba. Its intracellular concentration was estimated to be 0.7 mM. The identification was made in perchloric acid extracts on the basis of 31P-NMR chemical shift values and their variations with pH, by addition of authentic compound and by hydrolysis with wheat phytase. Perchloric acid extracts were prepared so as to avoid losses of insoluble salts of polyphosphorylated compounds with divalent cations. The glycolytic intermediate, 3-phosphoglycerate accumulated intracellularly in amoebae incubated in the presence of fluoride. The pH sensitive NMR signal of 3-phosphoglycerate was used to monitor cytosolic pH and a value of pH 7.4 was found in aerobic Dictyostelium amoebae.
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PMID:Identification of inositol hexaphosphate in 31P-NMR spectra of Dictyostelium discoideum amoebae. Relevance to intracellular pH determination. 282 May 8

A (31)P NMR method for quantitative determination of inositol phosphates in simple incubation samples of sodium phytate and Aspergillus niger phytase and in different types of complex samples, such as diets, digesta, and feces, is described. The inositol phosphates in complex samples were extracted with HCl, concentrated, and purified using freeze-drying and filtration and subsequently determined at pH 12.6 in aqueous solution using a (31)P NMR method. The (31)P NMR technique has as its main advantages over the HPLC techniques that it does not necessitate standards that may cause background matrix effects and that the spectra of inositol phosphates and orthophosphate appear in the same run without further sampling errors. The results of inositol hexaphosphate analysis with HPLC can be confirmed by this (31)P NMR method. Contents of inositol tetra-, tri-, di-, and monophosphate in the biological samples appear to be quantitatively not important. The (31)P NMR method can be applied for use in animal nutrition in general and studies of using phytase in diets for farm animals in particular, by measuring the content of inositol phosphates in feed ingredients, complete feeds, ileal contents, and feces of pigs and poultry.
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PMID:Quantification of inositol phosphates using (31)P nuclear magnetic resonance spectroscopy in animal nutrition. 1060 82

Inositol phosphates from barley low-phytate grain mutants and their parent variety were analysed by metal-dye detection HPLC and NMR. Compound assignment was carried out by comparison of retention times using a chemical hydrolysate of phytate [Ins(1,2,3,4,5,6)P(6)] as a reference. Co-inciding retention times indicated the presence of phytate, D/L-Ins(1,2,3,4,5)P(5), Ins(1,2,3,4,6)P(5), D/L-(1,2,4,5,6)P(5), D/L-(1,2,3,4)P(4), D/L-Ins(1,2,5,6)P(4) and D/L-Ins(1,4,5,6)P(4) in PLP1B mutants as well as the parent variety. In grain extracts from mutant lines PLP1A, PLP2A and PLP3A unusual accumulations of D/L-Ins(1,3,4,5)P(4) were observed whereas phytate and the above-mentioned inositol phosphates were present in relatively small amounts. Assignment of D/L-Ins(1,3,4,5)P(4) was corroborated by precise co-chromatography with a commercial Ins(1,3,4,5)P(4) standard and by NMR spectroscopy. Analysis of inositol phosphates during grain development revealed accumulation of phytate and D/L-Ins(1,3,4,5)P(4), which suggested the tetrakisphosphate compound to be an intermediate of phytate synthesis. This assumption was strengthened further by phytate degradation assays showing that D/L-Ins(1,3,4,5)P(4) did not belong to the spectrum of degradation products generated by endogenous phytase activity. Metabolic scenarios leading to accumulation of D/L-Ins(1,3,4,5)P(4) in barley low-phytate mutants are discussed.
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PMID:Inositol phosphates from barley low-phytate grain mutants analysed by metal-dye detection HPLC and NMR. 1117 Nov 28

Cells of Candida krusei capable of producing phytase were immobilized in Ca-alginate gel beads and used for the preparation of myo-inositol phosphates. The immobilization yield was increased about 5-fold after the beads were treated for 96 h at pH 4.0, 4 degrees C. The increased yield was retained, even after 1 month, when the cells were kept at this temperature and pH. No shift in the pH optima of phytase of the immobilized cells was observed, compared with that of free cells. However, the optimum temperature for the enzyme of the immobilized cells was 55 degrees C, which was 15 degrees C higher than that of free cells. The degradation characteristics of the phytate in immobilized cells packed in a glass column (i.d. 1.2 cm, length 20 cm) were investigated. The variation in the composition of the products results from a change in the flow rate of phytate solution (5 mM). At a flow rate of 1.30 ml/min, a mixture of myo-inositol-2-monophosphate, myo-inositol-1,2,5-triphosphate and myo-inositol-1,2,5,6-tetrakisphosphate was produced, in which the latter two were physiologically active. Also, it was found by NMR analysis that the enzyme of this strain produced only one isomer of each of the inositol phosphates, with the exception of myo-inositol pentakisphosphate. Therefore, the pure isomers were easily isolated using ion-exchange chromatography.
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PMID:Immobilization of Candida krusei cells producing phytase in alginate gel beads: an application of the preparation of myo-inositol phosphates. 1270 34

myo-Inositol hexaphosphate (IP6) is the main source of phosphorus in cereal grains, and therefore, in bakery products. Different microorganisms such as yeasts and lactic acid bacteria have phytase enzymes able to hydrolyze IP6 during the wholemeal breadmaking. In this paper, the phytase activity of Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus curvatus, and Saccharomyces cerevisiae strains, isolated from southern Italian sourdoughs, is assayed using the (31)P NMR technique. The sourdough technology based on the use of lactic acid bacteria in the breadmaking is finally suggested.
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PMID:Phytate degradation by lactic acid bacteria and yeasts during the wholemeal dough fermentation: a 31P NMR study. 1545 4

A phytase from Candida krusei WZ-001 isolated from soil was purified to electrophoretic homogeneity by ion-exchange chromatography, hydrophobic interaction chromatography, and gel filtration. The phytase is composed of two different subunits with molecular masses of 116 kDa and 31 kDa on SDS-PAGE (or 120 kDa and 30 kDa on gel chromatography), with the larger subunit having a glycosylation rate of around 35%. The phytase has an optimum pH of 4.6, an optimum temperature of 40 degrees C and a pI value of 5.5. The phytase activity was stimulated by 2-mercapto-ethanol and dithiothreitol (DTT), and inhibited by Zn2+, Mg2+, iodoacetate, pI value of 5.5. The phytase activity was stimulated by 2-mercapto-ethanol ethanol and dithiothreitol (DTT), and inhibited by Zn2+, Mg2+, iodoacetate, p-chroloromercuribenzoate (pCMB) and phenylmethylsulfonyl fluoride (PMSF). The phytase displayed a broad substrate specificity and the K(m) for phytate was 0.03 mM. Phytate was sequentially hydrolyzed by the phytase. Furthermore, 1D and 2D NMR analyses and bioassay of myoinositol indicated that the end hydrolysis product of phytate was myoinositol 2-monophosphate.
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PMID:Purification and properties of a phytase from Candida krusei WZ-001. 1623 28

myo-Inositol hexakisphosphate (InsP6) was hydrolyzed by a novel phytase purified from Candida krusei. The chemical structures of the product (InsP(1-5)) were identified by an NMR technique. The data indicate that the products from the enzyme catalytic reaction in sequence are D/L-Ins(1,2,4,5,6)P5, D/L-Ins(1,2,3,5,6)P5, D/L-Ins(1,2,5,6)P4, D/L-Ins(1,2,5)P3, D/L-Ins(1,2)P2 and D/L-Ins(2)P1.
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PMID:Pathway of dephosphorylation of myo-inositol hexakisphosphate by a novel phytase from Candida krusei WZ-001. 1623 51

A fungus producing high levels of phytase was isolated from air and identified as Cladosporium sp. The phytase production was stimulated by phytate in the medium used. The maximum production of phytase (108 U/ml) occurred in a medium containing 1.0 g of phytate per 100 ml. The phytase was purified to electrophoretic homogeneity by ion-exchange chromatography and gel filtration. Based on SDS-PAGE analysis, the molecular weight of the purified phytase was calculated to be approximately 32.6 kDa, and the narrow protein band indicated that this phytase is not glycosylated. The phytase has an optimum pH of 3.5, and an optimum temperature of 40 degrees C. The phytase activity was stimulated by 2-mercaptoethanol and dithiothreitol, and inhibited by Ba2+, Pb2+, iodoacetate, p-chloromercuribenzoate and phenylmethylsulfonyl fluoride. The phytase displayed high affinity for phytate and the Km was 15.2+/-3.1 microM. NMR analyses (1D and 2D) indicated that the end hydrolysis product of phytate was myo-inositol 1,2,5-triphosphate.
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PMID:Purification and properties of a low-molecular-weight phytase from Cladosporium sp. FP-1. 1623 25

Inositol phosphates are recognized as having diverse and critical roles in biological systems. In this report, kinetic studies and TLC analysis indicate that beta-propeller phytase is a special class of inositol phosphatase that preferentially recognizes a bidentate (P-Ca(2+)-P) formed between Ca(2+) and two adjacent phosphate groups of its natural substrate phytate (InsP(6)). The specific recognition of a bidentate chelation enables the enzyme to sequentially hydrolyze one of the phosphate groups in a bidentate of Ca(2+)-InsP(6) to yield a myo-inositol trisphosphate (InsP(3)) and three phosphates as the final products. A comparative analysis of (1)H- and (13)C NMR spectroscopy with the aid of 2D NMR confirms that the chemical structure of the final product is myo-Ins(2,4,6)P(3). The catalytic properties of the enzyme suggest a potential model for how the enzyme specifically recognizes its substrate Ca(2+)-InsP(6) and produces myo-Ins(2,4,6)P(3) from Ca(2+)-InsP(6). These findings potentially provide evidence for a selective Ca(2+)-InsPs chelation between Ca(2+) and two adjacent phosphate groups of inositol phosphates.
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PMID:Ca(2+)-inositol phosphate chelation mediates the substrate specificity of beta-propeller phytase. 1687 87

(3R,4S)-5-Fluoro-5-deoxy-D-ribulose-1-phosphate (5-FDRulP) has been identified as the third fluorinated intermediate on the biosynthetic pathway to fluoroacetate and 4-fluorothreonine in Streptomyces cattleya. 5-FDRulP is generated after formation of 5'-fluoro-5'-deoxyadenosine (5'-FDA) and then phosphorolysis of 5'-FDA to 5-fluoro-5-deoxy-D-ribose-1-phosphate (5-FDRP) by the action of a purine nucleoside phosphorylase. An isomerase mediates the conversion of 5-FDRP to 5-FDRulP. The identity of the (3R,4S) diastereoisomer of 5-FDRulP was established by comparative (19)F{(1)H} NMR studies whereby 5-FDRulP that accumulated in a cell free extract of S. cattleya, was treated with a phytase to generate the non-phosphorylated sugar, 5-fluoro-5-deoxy-D-ribulose (5-FDRul). This S. cattleya product was compared to the product of an in-vitro biotransformation where separately 5-fluoro-5-deoxy-D-ribose and 5-fluoro-5-deoxy-D-xylose were converted to 5-fluoro-5-deoxy-D-ribulose and 5-fluoro-5-deoxy-D-xylulose respectively by the action of glucose isomerase. It was demonstrated that 5-fluoro-5-deoxy-D-ribose gave the identical diastereoisomer to that observed from 5-FDRulP.
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PMID:The identification of (3R,4S)-5-fluoro-5-deoxy-D-ribulose-1-phosphate as an intermediate in fluorometabolite biosynthesis in Streptomyces cattleya. 1757 46


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