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)

An extracellular acid phosphatase isolated from the culture of a wild strain Aspergillus niger, producing the dephosphorylating 3-phytase, was obtained in a homogeneous form by sequential application of ultrafiltration through PS 50 membrane, gel filtration on Sephadex G-100 and ion exchange chromatography on DEAE-Sepharose CL 6B and CM-Sepharose CL 6B. The enzyme showed a maximum catalytic value in a strongly acidic range (pH 2.0-2.4) with pHopt 2.1 and topt 66 degrees C. The acid phosphatase showed a wide substrate specificity and a high affinity for sodium phytate, 2.5x higher than with 4-nitrophenyl phosphate. This property of the acid phosphatase demonstrated that it is a potent 3-phytase at pH 2.1 and is of great significance for a practical application of the dephosphorylating complex--its addition to the diets of monogastric animals in view of the low pH values in the digestive tract.
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PMID:Aspergillus niger pH 2.1 optimum acid phosphatase with high affinity for phytate. 1745 90

Acid phosphatase activity was detected in peanut (Arachis hypogaea) cotyledons during germination. Four (4) to six (6) days of germination was the meantime corresponding to maximum hydrolytic activity of this enzyme. The understanding of the role of acid phosphatase activity during germination led to purify this enzyme by successive chromatography separations on DEAE-Sepharose CL-6B, Sephacryl S-100 HR and Phenyl-Sepharose HP to apparent homogeneity from germinated peanut cotyledon five days old. This enzyme designated peanut cotyledon acid phosphatase (AP) had native molecular weight of 24 kDa by gel permeation. SDS-PAGE of the purified acid phosphatase resolved a single protein band that migrated to approximately 21.5 kDa. Thus, this acid phosphatase likely functions as a monomer. The enzyme had optimum pH (5.0) and temperature (55 degrees C), and appeared to be stable in the presence of anionic, cationic and non-ionic detergents. Substrate specificity indicated that the purified acid phosphatase hydrolyzed a broad range of phosphorylated substrates. However, natural substrates such as ADP and ATP were the compounds with highest rate of hydrolysis for the enzyme. Moreover, the purified acid phosphatase exhibited phytase activity. These results showed that this enzyme played a peculiar role during germination, notably in reducing the rate of phytic acid, an antinutritional substance contained in peanut seed.
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PMID:Purification, kinetic properties and physicochemical characterization of a novel acid phosphatase (AP) from germinating peanut (Arachis hypogaea) seed. 1772 56

An acid phosphatase with phytase activity, produced by Mucor hiemalis Wehmer, was purified to homogeneity by a combination of anion exchange, gel filtration and hydrophobic interaction chromatography. The monomeric, glycosylated enzyme displayed maximum activity at 55 degrees C and pH 5.0-5.5. When compared to commercialised products, the enzyme is more thermostable (80 degrees C, 5min), displays a broader pH versus activity profile and greater stability under simulated digestive tract conditions. Unlike commercial phytases, the Mucor enzyme should retain some activity in the small intestine as well as in the stomach, facilitating a longer duration of action and hence more extensive substrate hydrolysis. Substrate specificity studies and protein database similarity searching using mass spectrometry-derived sequence data indicate that the enzyme is an acid phosphatase with activity on phytate. Cocktails containing acid phosphatases in combination with true phytases have been shown to promote more extensive phytate degradation than do true phytases alone. This, coupled to the enzyme's functionally relevant physicochemical characteristics, suggests its likely suitability for inclusion in second generation phytase cocktails for application in animal feed.
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PMID:Purification and characterisation of an acid phosphatase with phytase activity from Mucor hiemalis Wehmer. 1788 94

Phytases are enzymes that catalyze liberation of inorganic phosphates from phytate, the major organic phosphorus in soil. Tobacco (Nicotiana tabacum) responds to phosphorus starvation with an increase in extracellular phytase activity. By a three-step purification scheme, a phosphatase with phytase activity was purified 486-fold from tobacco root exudates to a specific activity of 6,028 nkat mg(-1) and an overall yield of 3%. SDS-PAGE revealed a single polypeptide of 64 kDa, thus indicating apparent homogeneity of the final enzyme preparation. Gel filtration chromatography suggested that the enzyme was a ca. 56 kDa monomeric protein. De novo sequencing by tandem mass spectrometry resulted in a tryptic peptide sequence that shares high homology with several plant purple acid phosphatases. The identity of the enzyme was further confirmed by molybdate-inhibition assay and cDNA cloning. The purified enzyme exhibited pH and temperature optima at 5.0-5.5 and 45 degrees C, respectively, and were found to have high affinities for both p-nitrophenyl phosphate (pNPP; K(m)=13.9 microM) and phytate (K(m)=14.7 microM), but a higher kcat for pNPP (2,056 s(-1)) than phytate (908 s(-1)). Although a broad specificity of the enzyme was observed for a range of physiological substrates in soil, maximum activity was achieved using mononucleotides as substrates. We conclude that the phytase activity in tobacco root exudates is exhibited by a purple acid phosphatase and its catalytic properties are pertinent to its role in mobilizing organic P in soil.
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PMID:Phytase activity in tobacco (Nicotiana tabacum) root exudates is exhibited by a purple acid phosphatase. 1789 89

The sweet potato sporamin promoter was used to control the expression in transgenic potato of the E. coli appA gene, which encodes a bifunctional enzyme exhibiting both acid phosphatase and phytase activities. The sporamin promoter was highly active in leaves, stems and different size tubers of transgenic potato, with levels of phytase expression ranging from 3.8 to 7.4% of total soluble proteins. Phytase expression levels in transgenic potato tubers were stable over several cycles of propagation. Field tests showed that tuber size, number and yield increased in transgenic potato. Improved phosphorus (P) acquisition when phytate was provided as a sole P source and enhanced microtuber formation in cultured transgenic potato seedlings when phytate was provided as an additional P source were observed, which may account for the increase in leaf chloroplast accumulation (important for photosynthesis) and tuber yield of field-grown transgenic potato supplemented with organic fertilizers. Animal feeding tests indicated that the potato-produced phytase supplement was as effective as a commercially available microbial phytase in increasing the availability of phytate-P to weanling pigs. This study demonstrates that the sporamin promoter can effectively direct high-level recombinant protein expression in potato tubers. Moreover, overexpression of phytase in transgenic potato not only offers an ideal feed additive for improving phytate-P digestibility in monogastric animals but also improves tuber yield, enhances P acquisition from organic fertilizers, and has a potential for phytoremediation.
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PMID:The sweet potato sporamin promoter confers high-level phytase expression and improves organic phosphorus acquisition and tuber yield of transgenic potato. 1838 77

Recurrent application of animal manure to the soil often results in accumulation of phosphorus (P) in the soil over time. Use of temperate forages like Lolium multiflorum capable of extracting excess P from manure impacted soil is an attractive strategy for P phytoremediation. Two genotypes of L. multiflorum, 'Gulf and Marshall' were grown in soil and hydroponic media containing various concentrations of poultry manure and their P accumulation potential was determined. A decline in the biomass with an increase in manure concentration beyond 10 g kg(-1) soil in Gulf and 25 g kg(-1) soil in Marshall was noticed. Gulf grass accumulated more P content (7 g kg(-1) dry weight) as compared to Marshall (6 g kg(-1) dry weight) in both roots and shoots. Maximum shoot P content was observed in the soil amended with 10 g poultry manure, while root P was highest at the concentration of 50 g poultry manure kg(-1) in the soil. Both cultivars yielded the highest biomass when grown in the presence of 10 g poultry manure in modified Hoagland's media. Presence of chelators in the media did not produce any noticeable effect on P accumulation in either grass and the biomass was appreciably enhanced by all concentrations of the chelators. Gulf and Marshall ryegrass seedlings were grown hydroponically in various poultry manure fractions. Both phytase and acid phosphatase (APase) enzyme activities in the root increased substantially in response to P-sufficient condition. In the presence of various poultry manure fractions, an intermediate level of both enzymes was measured compared to the P-sufficient condition, while the lowest enzyme activity was observed in the absence of any P source in the media. The level of APase and phytase activities was more or less the same in the two grasses under various growth conditions. An additional APase isoform was induced specifically in response to P-starvation from the two grass cultivars. Phytase and APase assays carried out in the P-starved and P-replenished grass seedlings further confirmed that during P deficiency, the enzyme activity was lowest and results of PAGE indicated that an APase isoform was induced under P-starvation.
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PMID:Effect of P sources on growth, P accumulation and activities of phytase and acid phosphatases in two cultivars of annual ryegrass (Lolium multiflorum L.). 1848 20

The mechanisms of action of phosphate solubilization were studied in the wild-type strain Aspergillus tubingensis and the phenotypic mutants derived from it. The P solubilization activities of these isolates were measured in liquid media using different carbon and nitrogen sources. All the mutants showed higher P solubilization compared to the wild type. Glucose and sucrose significantly promoted P solubilization compared to fructose, lactose, galactose, and xylose. Potassium nitrate significantly increased P solubilization compared to other nitrogen sources such as ammonium sulfate, ammonium nitrate, aspargine, and tryptophan. The P solubilization activity was strongly associated with the production of organic acids, especially succinic acid and acetic acid. The enzyme activities such as acid phosphatase and phytase also increased significantly in mutants compared to the wild type. These results suggested the role of these enzymes in P solubilization apart from the organic acid exudation and H+ pump in A. tubingensis.
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PMID:Effect of carbon and nitrogen sources on phosphate solubilization by a wild-type strain and UV-induced mutants of Aspergillus tubingensis. 1866 23

In a changing scenario of food habits being associated with wellness factors through the concepts of probiotics and prebiotics, an attempt has been made to characterize on molecular basis, the desirable benefits associated with natural isolates of lactic acid bacteria, bifidobacteria, and yeasts. From a diverse range of foods and related samples, based on conventional microbiological protocols, three well-characterized natural isolates of Lactobacillus plantarum MTCC 5422, Bifidobacterium adolescentis MTCC 5423 and Saccharomyces cerevisiae MTCC 5421 were selected. The cultures of L. plantarum and B. adolescentis showed positive polymerase chain reaction (PCR) amplification with oligonucleotide primers targeting genus-specific 16 S rRNA for Lactobacillus and fructose-6-phosphate phosphoketolase for Bifidobacterium. Similarly, species-specific positive amplification in PCR was observed with primers of phytase (acid phosphatase) in S. cerevisiae and alpha-D: -galactosidase and bile salt hydrolase in L. plantarum and B. adolescentis. The cultures of L. plantarum and B. adolescentis exhibited a broad spectrum antibacterial activity against selected foodborne pathogenic bacterial species and tolerance to acid and bile. Gene sequence of respective PCR-amplified products confirmed the genetic identity of the isolated cultures as L. plantarum and B. adolescentis showing 99% homology with the documented sequence of established gene bank.
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PMID:Molecular characterization of native isolates of lactic acid bacteria, bifidobacteria and yeasts for beneficial attributes. 1940 95

This study was undertaken to screen and select potent phytate degrading lactic acid bacteria and to evaluate their additional characteristic features. Forty lactic acid bacterial strains were isolated from different sources and screened for their ability to degrade myo-inositol hexaphosphate or IP(6) by cobalt chloride staining (plate assay) method, using calcium or sodium salt of phytic acid as substrate. All the forty isolates were able to degrade calcium phytate. However, only two Pediococcus pentosaceus strains (CFR R38 and CFR R35) were found to degrade sodium phytate. These strains showed phytase activity of 213 and 89 U at 50 degrees C, respectively and poor acid phosphatase activity. These strains were further evaluated for additional characteristic features. At pH 2, P. pentosaceus strains CFR R38 and CFR R35 showed 50.7 and 48.5 percentage survivability after 2 h of incubation respectively and they could also withstand 0.3% ox-bile. These cultures exhibited 54.6 and 44.8% of hydrophobicity to xylene, antibacterial activity against food borne pathogens and possessed beta-galactosidase activity. The resistance pattern to several antibiotics was also analyzed. The present study indicates that these strains, having phytate degrading ability and other characteristic features can be exploited as starter cultures in fermented foods to improve the mineral bioavailability.
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PMID:Screening, selection and characterization of phytic acid degrading lactic acid bacteria from chicken intestine. 1948 Dec 82

Purple acid phosphatase (PAP) catalyzes the hydrolysis of phosphate monoesters and anhydrides to release phosphate within an acidic pH range. Among the 29 PAP-like proteins in Arabidopsis (Arabidopsis thaliana), AtPAP15 (At3g07130) displays a greater degree of amino acid identity with soybean (Glycine max; GmPHY) and tobacco (Nicotiana tabacum) PAP (NtPAP) with phytase activity than the other AtPAPs. In this study, transgenic Arabidopsis that expressed an AtPAP15 promoterbeta-glucuronidase (GUS) fusion protein showed that AtPAP15 expression was developmentally and temporally regulated, with strong GUS staining at the early stages of seedling growth and pollen germination. The expression was also organ/tissue specific, with strongest GUS staining in the vasculature, pollen grains, and roots. The recombinant AtPAP purified from transgenic tobacco exhibited broad substrate specificity with moderate phytase activity. AtPAP15 T-DNA insertion lines exhibited a lower phytase and phosphatase activity in seedling and germinating pollen and lower pollen germination rate compared with the wild type and their complementation lines. Therefore, AtPAP15 likely mobilizes phosphorus reserves in plants, particularly during seed and pollen germination. Since AtPAP15 is not expressed in the root hair or in the epidermal cells, it is unlikely to play any role in external phosphorus assimilation.
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PMID:Molecular and biochemical characterization of AtPAP15, a purple acid phosphatase with phytase activity, in Arabidopsis. 1963 33


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