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)

InsP6 is an abundant compound in many micro-organisms, plants and animal cells. Its function and route of synthesis are still largely unknown. Degradation of InsP6 is mediated by phytase, which in most organisms dephosphorylates InsP6 in a relatively non-specific way. In the micro-organism Paramecium, however, the enzyme has been shown to dephosphorylate InsP6 to InsP2 in a specific order, but its stereospecificity has not been established, i.e. the phosphates are removed in the sequence 6/5/4/3 or 6/5/4/1 or 4/5/6/1 or 4/5/6/3 [Freund, Mayr, Tietz and Schultz (1992) Eur. J. Biochem. 207, 359-367]. We have isolated the InsP4 intermediate and identified its absolute configuration as D-Ins(1,2,3,4)P4. Furthermore, degradation of [3,5-32P]InsP6 yielded a 32P-labelled InsP2 isomer, D-Ins(2,3)P2. These data demonstrate that Paramecium phytase removes the phosphates of InsP6 in the sequence 6/5/4/1. Knowing the stereochemical course of the enzyme, it can be used to elucidate the route of InsP6 synthesis, as it allows us to determine the specific radioactivity at individual positions of the molecular after pulse-labelling cells with [32P]P1 in vivo or [gamma-32P]ATP in vitro.
Biochem J 1995 Dec 15
PMID:Stereospecificity of inositol hexakisphosphate dephosphorylation by Paramecium phytase. 855 37

Although many cells contain large amounts of InsP6, its metabolism and function is still largely unknown. In Dictyostelium lysates, the formation of InsP6 by sequential phosphorylation of inositol via Ins(3,4,6)P3 has been described [Stevens and Irvine (1990) Nature (London) 346, 580-583]; the second messenger Ins(1,4,5)P3 was excluded as a potential substrate or intermediate for InsP6 formation. However, we observed that mutant cells labelled in vivo with [3H]inositol showed altered labelling of both [3H]Ins(1,4,5)P3 and [3H]InsP6. In this report we demonstrate that Ins(1,4,5)P3 is converted into InsP6 in vitro by nucleus-associated enzymes, in addition to the previously described stepwise phosphorylation of inositol to InsP6 that occurs in the cytosol. HPLC analysis indicates that Ins(1,4,5)P3 is converted into InsP6 via sequential phosphorylation at the 3-, 6- and 2-positions. Ins[32P]P6, isolated from cells briefly labelled with [32P]Pi, was analysed using Paramecium phytase, which removes the phosphates of InsP6 in a specific sequence. The 6-position contained significantly more 32P radioactivity than the 4- or 5-positions, indicating that the 6-position is phosphorylated after the other two positions. The results from these in vivo and in vitro experiments demonstrate a metabolic route involving the phosphorylation of Ins(1,4,5)P3 via Ins(1,3,4,5)P4 and Ins(1,3,4,5,6)P5 to InsP6 in a nucleus-associated fraction of Dictyostelium cells.
Biochem J 1995 Dec 15
PMID:Nucleus-associated phosphorylation of Ins(1,4,5)P3 to InsP6 in Dictyostelium. 855 38

Obtaining high quality protein crystals remains a rate-limiting step in the determination of three-dimensional X-ray structures. A frequently encountered problem in this respect is the high or heterogeneous carbohydrate content of many eukaryotic proteins. A number of reports have demonstrated the use of enzymatic deglycosylation in the crystallization of certain glycoproteins. Although this is an attractive tool, there are some problems that hinder the more widespread use of glycosidases in crystallization. First, commercially available glycosidases are relatively expensive, which virtually prohibits their use on a large scale. Second, the glycosidase must be removed from the glycoprotein of interest following deglycosylation, which is not always straightforward. To circumvent these problems we have cloned the two most generally useful glycosidases, peptide-N-glycosidase F and endoglycosidase F1 from Flavobacterium meningosepticum, as fusion proteins with glutathione S-transferase. The fusion not only allows rapid purification of these enzymes from Escherichia coli cell extracts, but also permits rapid removal from target proteins following deglycosylation. We have used these enzymes to obtain crystals of phytase from Aspergillus ficuum and acid phosphatase from Aspergillus niger and to obtain a new crystal form of recombinant human renin.
Protein Sci 1996 Dec
PMID:Deglycosylation of proteins for crystallization using recombinant fusion protein glycosidases. 897 70

Young pigs (5 wk of age and 8 kg) were used to test the efficacy of 1 alpha-hydroxycholecalciferol (1 alpha-OH D3) and microbial phytase for improving the utilization of phytate phosphorus (P) and amino acids present in corn-soybean meal (SBM) diets. Phytase supplementation (1,200 units/kg) to a vitamin D3-adequate, P-deficient corn-SBM diet elicited a marked response (P < .05) in weight gain and ash content of fibula, scapula, and metatarsal bones, but dietary addition of 1 alpha-OH D3 (20 micrograms/kg) was without effect. A P- and vitamin D3-adequate, amino acid-deficient corn-SBM diet (15.5% CP) also was supplemented with 1,200 units/kg of phytase to evaluate the efficacy of phytase in improving amino acid utilization. Pigs gained faster (P < .05) and more efficiently (P < .05) when this diet was supplemented with limiting amino acids, and phytase addition also increased (P < .05) weight gain, regardless of whether the diet was deficient or adequate in amino acids. Feed efficiency was improved (P < .05) by phytase addition to the amino acid-deficient diet but not to the amino acid-adequate diet. Pigs fed the low-CP, amino acid-fortified diet gained as fast and as efficiently as those fed a 19.5% CP (1.19% lysine) positive-control diet.
J Anim Sci 1996 Dec
PMID:Efficacy of supplemental 1 alpha-hydroxycholecalciferol and microbial phytase for young pigs fed phosphorus- or amino acid-deficient corn-soybean meal diets. 899 10

A 3-wk feeding trial with 240 sexed, day-old broiler chickens was conducted to determine the efficacy of microbial phytase at different levels of dietary Ca on performance and utilization of minerals in broiler chickens fed a low-P corn-soybean diet. The experimental design was a 3 x 2 factorial arrangement of treatments; Ca at 0.6, 1.0, and 1.25% and phytase at 0 and 600 phytase U/kg diet. Phytase supplementation, regardless of Ca level, increased (P < or = 0.005) feed intake, (P < or = 0.0001) body weight, and (P < or = 0.025) feed efficiency at 21 d; the optimum levels of body weight, feed intake, and feed efficiency were obtained with low (0.6%) dietary Ca plus phytase. Retentions of P, Ca, and N were increased (P < or = 0.05) by phytase supplementation. Although maximum retentions of P and N were obtained at the 1.0 and 1.25% Ca levels, respectively, they were not significantly different from the values obtained at 0.6% Ca. The increasing level of dietary Ca decreased plasma P ( P < or = 0.05) and Cu (P < or = 0.06). Phytase supplementation had the opposite effect; i.e., increased plasma P (P < or = 0.03) and Cu (P < or = 0.02). The maximum level of plasma P was obtained with phytase at the 1.0% Ca level, but this value was not significantly different from the value obtained with phytase at the 0.6% Ca level. Phytase supplementation increased (P < 0.04) the ash content of both tibia head and shaft but had no effect on mineral contents in the ash. The optimum level of ash content was observed with the 0.06% Ca diet plus phytase. The results show that microbial phytase supplementation to a low P diet improved growth performance and mineral utilization in broiler chickens. Dietary Ca levels had a significant effect on the response to phytase; the optimum growth performance and mineral utilization were achieved at the low (0.6%) level of dietary Ca supplemented with phytase.
Poult Sci 1996 Dec
PMID:Efficacy of supplemental microbial phytase at different dietary calcium levels on growth performance and mineral utilization of broiler chickens. 900 Feb 77

Two experiments using 413 crossbred growing-finishing pigs were conducted to assess the use of a commercial microbial phytase (Natuphos) in corn-soybean meal diets to improve phytate P bioavailability and thus reduce inorganic P supplementation and fecal P excretion. In Exp. 1 (n = 189), the following diets were used: 1) .50/.40% total P, respectively, for grower and finisher phases, and no phytase; 2) .40/.35% P and no phytase; 3) diet 2 plus 250 U phytase/kg; and 4) diet 2 plus 500 U phytase/ kg. The total Ca level was .58/.48% for diet 1 and .53/.43% Ca for diets 2, 3, and 4 in the grower and finisher phases, respectively. Feeding the low-P diet without supplemental phytase resulted in an overall 18% reduction in ADG (P < .05), 15% reduction in ADFI (P < .05), and 3% poorer feed efficiency (P < .08). Adding 250 to 500 U phytase/kg to the low-P diet restored ADG, ADFI, and feed conversion to levels not significantly different from and within 96% of that observed for pigs fed the adequate-P diet. The overall apparent digestibility of P was linearly (P < .01) improved with addition of 250 and 500 U phytase/kg to the low-P diet, but Ca and DM digestibilities were not affected by phytase or P level. In Exp. 2 (n = 224) the following diets were used: 1) .38/.33% total P, respectively, for grower and finisher phases, and no phytase; 2) .42/.37% P and no phytase; 3) .46/.41% P and no phytase; 4) diet 1 plus 167 U/kg phytase; 5) diet 1 plus 333 U/kg phytase; and 6) diet 1 plus 500 U/kg phytase. All diets contained .41/.36% Ca for grower and finisher phases, respectively. Pigs fed the low-P control diet grew slower (P < .01) and less efficiently (P < .10) than pigs fed diets with added P or phytase. With increasing levels of supplemental phytase or P there was a linear increase (P < .01) in ADG, digestibility of P, and digested P and a quadratic improvement (P < .05) in feed efficiency. Tenth rib mineralization based on shear force and ash were linearly increased (P < .08 to .001) as phytase or P was added to the low-P diet. There were generally no effects of P or phytase level on carcass quality. Using prediction equations derived from the response traits of ADG and P digestibility in Exp. 1 and ADG, P digestibility, and bone shear force in Exp. 2 to added phytase or P, we estimated that 500 U phytase released an amount of phytate P that was approximately equivalent to .87 to .96 g of P from dicalcium-monocalcium phosphate supplements. Fecal P excretion was estimated to be reduced 21.5%.
J Anim Sci 1997 Dec
PMID:Phytase supplementation of low-phosphorus growing-finishing pig diets improves performance, phosphorus digestibility, and bone mineralization and reduces phosphorus excretion. 941 91

The effect of microbial phytase supplementation on CP and amino acid (AA) digestibility was investigated in a 28-d trial using 360 sexed, day-old broiler chickens fed corn-soybean meal diets. The experimental design was a completely randomized one with a 3 x 2 factorial arrangement of treatments. The variables included P and Ca levels and phytase: P and Ca levels were: normal P-normal Ca [0.45% available P (Pa), 1.0% Ca], low P-normal Ca (0.35% Pa, 1.0% Ca), and low P-low Ca (0.35 Pa and 0.6% Ca); and phytase at 0 and 600 U/kg diet. Phytase supplementation increased body weight gain (P < 0.014) and feed intake (P < 0.004) at 19 d in male chickens; in females, phytase increased (P < 0.012) only body weight gain at 19 d. The low P-normal Ca diet reduced (P < 0.05) feed intake and body weight gain in both sexes at 7, 14, and 19 d, compared to the normal P-normal Ca diet; the reduction of Ca in the low P diet prevented the above depression, resulting in body weight gain and feed intake to a level comparable to that of the normal P-normal Ca diet. Microbial phytase supplementation had no effect (P < 0.065) on the apparent ileal digestibility (AID) of CP or any AA except Met and Phe in male broiler chickens. In females, adding phytase increased the AID of all AA except Lys, Met, Phe, and Pro. The low P-normal Ca diet reduced (P < 0.05) the AID of Phe, Asp, and Ser in male chickens and reduced the AID of all the AA except Met and Pro in females compared to the normal P-normal Ca diet. The reduction of Ca in the low P diet prevented the depression of the AID of the AA caused by the low P-normal Ca diet, resulting in AID of AA having a level comparable to that of the normal P-normal Ca diet in both sexes. Phytase supplementation did not have any effect (P > 0.05) on apparent "fecal" digestibility (AFD) of CP or any of the AA in male chickens; however, in female chickens it increased the AFD of Thr, Asp, Glu, and Ser. In summary, phytase supplementation increased growth performance in both sexes; increased AID and AFD of most of the AA, particularly in female chickens. The optimum growth performance and AA digestibilities were obtained with the lowest input of resources, in the low P-low Ca diet supplemented with microbial phytase.
Poult Sci 1997 Dec
PMID:Apparent digestibility of protein and amino acids in broiler chickens fed a corn-soybean diet supplemented with microbial phytase. 943 93

Two trials were conducted to determine the effects on broiler chicken performance and health of reducing dietary phosphorus levels by treating feed with the enzyme phytase, formulating diets using high available phosphorus (HAP) corn, or when diets were formulated with HAP corn and treated with phytase. Cobb x Cobb male broiler chickens were placed in an experimental design consisting of four dietary treatments with six replicate pens of 50 broilers per pen. The dietary treatments consisted of untreated control feed, phytase-supplemented feed (500 U/kg), diets prepared with HAP corn, and diets prepared with HAP corn and supplemented with phytase. The chickens were maintained on these dietary treatments from 1 to 49 d of age with feed and water made available for ad libitum consumption. When the two trials were combined, there was a significant (P < or = 0.05) increase in body weight in the broilers fed the phytase treated diets at 49 d of age. The serum activity of alkaline phosphatase was significantly decreased in the diets supplemented with phytase, and serum cholesterol was significantly decreased in the diets prepared with HAP corn. These data indicate that total phosphorus can be reduced by at least 11% in diets prepared with HAP corn, or in diets supplemented with phytase, without affecting the performance or health of broiler chickens. When diets are prepared with HAP corn and supplemented with phytase, the dietary addition of total phosphorus can be reduced by at least 25% without affecting broiler chicken performance or health.
Poult Sci 1998 Dec
PMID:Effect of dietary phytase and high available phosphorus corn on broiler chicken performance. 987 94

1. In the first of 2 experiments ducklings grown from 2 to 19 d were given diets with 0, 200 or 400 g rice bran, with or without a phytase and with 1 or 3 g inorganic phosphorus (Pi) per kg for rice bran-based diets only. In the 2nd experiment rice bran concentrations were 0, 300 or 600 g rice bran per kg with or without a phytase and 1 g Pi/kg. Ducks were grown from 19 to 40 d of age. 2. In experiment 1, a response to phytase was observed for weight gain and food intake on most diets except those with 200 g rice bran (3 g Pi) and 4.00 g rice bran (1 g P)i/kg. Main effects showed that 400 g rice bran depressed growth rate and food conversion ratio (FCR); increasing Pi depressed food intake, while food phytase increased food intake and growth rate over 2 to 19 d. There were several interactions. Dry matter and P retention were reduced but N digestibility improved when rice bran was increased from 200 g to 400 g/kg at 2 to 10 d of age; apparent metabolisable energy (AME) and calcium retentions were improved, similar results being seen at 10 to 19 d of age. Calcium and P retentions increased with the addition of food phytase and, at 10 to 19 d of age, phytase increased dry matter digestibility. Increasing Pi improved calcium and P retention, but only at 2 to 10 d of age. 3. Tibia ash (g or g/kg) content of bone was lowest on the diet without rice bran and without phytase; Pi concentration had no effect but phytase increased tibia ash on diets with 0 and 200 g rice bran and 1 g Pi/kg. Retention of several minerals in tibia ash declined at the highest rice bran inclusion rate; Pi level and phytase both increased Mg retention. 4. In experiment 2, food intake and growth rate of ducks, but not FCR, declined as rice bran inclusion increased from 0 to 600 g/kg. Phytase improved growth rate but not food intake and FCR on all 3 diets. Dry matter digestibility declined with increasing rice bran inclusion, but AME increased; retention of P and Mg declined but those of Ca and Fe increased. Phytase improved dry matter digestibility and retention of N and P. AME also increased but this was only on diets with 0 and 600 g rice bran/kg. There were reductions of 8% and 10% in P excreted in experiments 1 and 2 respectively when food phytase was added. 5. Tibia ash declined with increasing dietary inclusion of rice bran. Zn and Mn in ash tended to decline and Mg to increase; Ca and P showed no change in concentration in tibia ash. Again, phytase increased tibia ash content in bone. 6. It was concluded that there were a number of unexpected benefits from adding a food phytase to these diets, which resulted in improved nutrient yield and bird performance, although several of the diets appeared to be adequate in available P.
Br Poult Sci 1998 Dec
PMID:Strategies to improve the nutritive value of rice bran in poultry diets. III. The addition of inorganic phosphorus and a phytase to duck diets. 992 12

1. Ducklings were given diets with vegetable protein (VP) and 0 or 600 g rice bran/kg; fish meal (60 g/kg) and a phytase (+, -) were added to the diets (VP + AP). An additional 40 g soyabean meal/kg was added to the diet with rice bran (VP ++). Amino acid digestibility and mineral retention were measured in the lower ileum of ducklings killed at 23 d of age. Acid insoluble ash was used as an inert marker. Trypsin and amylase activities were also measured and weights of the pancreas and small intestine recorded at slaughter. 2. Addition of soyabean meal (VP ++) to the diet with rice bran improved growth rate and food intake compared to the diet without (VP) and gave the same food intake and growth rate as the comparable basal diet (VP) without rice bran. Fish meal improved growth rate on the diets without rice bran and improved food intake on this diet (VP + AP). Rice bran depressed growth rate and food conversion ratio (FCR); protein source affected growth rate, food intake and FCR; phytase increased food intake only. There were several interactions. 3. Determined total amino acid composition of the diets appeared to meet the essential amino acid requirements of ducklings. Rice bran depressed the ileal digestibility of virtually all amino acids and phytase had no direct effect, although there were interactions. Fish meal addition to diets with rice bran improved the apparent digestibility of several essential amino acids as well as that of dry matter and crude protein. 4. Ileal retention of some minerals and tibia ash content were reduced by rice bran. Fish meal and phytase inclusion increased P retention and ash in tibia. 5. Higher intestinal trypsin activity and increased pancreas size were seen in ducklings on diets with rice bran compared to those without. Intestinal amylase activity was reduced in ducklings given rice bran, probably because of its low starch content. 6. The stimulating effect of fish meal on duckling performance was probably caused in part by the improvement in the digestibility of some amino acids. The addition of small amounts of minerals in fish meal may have increased mineral retention. Phytase gave benefits anticipated from our previous work, but also improved lysine and threonine digestibility in diets containing vegetable protein only.
Br Poult Sci 1998 Dec
PMID:Strategies to improve the nutritive value of rice bran in poultry diets. IV. Effects of addition of fish meal and a microbial phytase to duckling diets on bird performance and amino acid digestibility. 992 13


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