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)

Phytase was purified from Aspergillus niger culture fluid by molecular sieve filtration on Sephadex G-200, followed by thermal inactivation of acid phosphatase and CM-cellulose chromatography. The 12-fold purified enzyme had two pH optima at 2.7 and 5.5 and was characterized by high thermal stability in alkaline environment and broad substrate specificity. The Michaelis constant of phytase relative to myo-inositol hexaphosphate sodium salt is 4.8 X 10(-4) M and activation energy 9,217 cal/mole. The molecular weight of the enzyme is estimated at 200,000.
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PMID:Some properties of partially purified phytase from Aspergillus niger. 7 23

A phytase (EC 3.1.3.8) was extracted from rat intestinal bacterium, Klebsiella Sp. No. PG.-2, and purified 50-fold by ammonium sulphate fractionation, ion-exchange chromatography and gel filtration. The enzyme is inducible in nature. The pH optimum was at 6.0 for all the inositol phosphates studied and this characterized the enzyme as an acid phosphohydrolase. Of a range of potential substrates tested, only p-nitrophenyl phosphate alongwith the inositol phosphates was hydrolyzed. It exhibits a Km of 2.0 mM; temperature optimum of 37 degrees C and energy of activation 9,120 cal/mole for all the inositol phosphates studied. The activity was inhibited by Ag2+, Hg2+, Cu2+, fluoride and high substrate concentration.
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PMID:Phytase from Klebsiella Sp. No. PG-2: purification and properties. 216 21

Information is needed on organic polyphosphates such as myo-inositol 1,2,3,5/4,6-hexakis dihydrogenphosphate or phytate (IP6) contribution to the sources and sinks of dissolved phosphorus (PO4-P) in the soil-manure-water system. Effects of Na+, Ca2+, Al3+, and Fe3+ and cation to IP6-P mole ratios on the enzymatic dephosphorylation of IP6 were studied to determine controlling mechanisms of dephosphorylation and persistence in manure. Phytate- and PO4-P were analyzed by high-performance liquid chromatography. Phytate dephosphorylation by Aspergillus ficuum (Reichardt) Henn. phytase EC 3.1.3.8 decreases by 50 +/- 3.6 and 40 +/- 4% at pH 4.5 and 6, respectively, as Ca2+ concentrations increase and cation to IP6-P mole ratios reach 6:6. Polyanionic IP6 has a high affinity for Al3+ and Fe3+ and reductions in dephosphorylation average 27 and 32% at a cation to IP6-P mole ratio of 1:6 for Al3+ and Fe3+, respectively, while reaching more than 99% at a mole ratio of 6:6. A phytase-hydrolyzable phosphorus (PHP) fraction is native to ruminant animal manure and is proportional to total solids (TS) concentration in 1 to 100 g L(-1) suspensions. Added phytase, in effect, increases water-extractable P content of manure and the risk of environmental P dispersion. As the bioavailability and ecological effect of IP6-P appear to be regulated not only by pH-controlled enzyme activity but also by the associated counterions, the differential protective effects of cations influence the accuracy of manure PHP fraction estimates and increase phytate resistance to enzymatic dephosphorylation that may lead to its persistence in manure.
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PMID:Polyvalent cation effects on myo-inositol hexakis dihydrogenphosphate enzymatic dephosphorylation in dairy wastewater. 1270 95

A phytase was isolated and partially purified from the pollen of Lilium longiflorum Thumb. Optimum activity was at pH 8.0. The phytase was activated by Ca(2+) and Sr(2+) but not by the other divalent cations tested. Activity was inhibited by ethylenediaminetetraacetate. The phytase had a temperature optimum of 55 to 60 degrees C and an activation energy of about 12,700 calories/mole. Extraction of L. longiflorum pollen with 0.1% Triton X-100 increased recovery of the phytase by nearly 4-fold. The phytase had a molecular weight of about 88,000 as determined by gel filtration chromatography and a K(m) value of 7.2 micromolar for phytic acid in the presence of Ca(2+).
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PMID:A Calcium-Activated Phytase from Pollen of Lilium longiflorum. 1666 18