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:3.5.1.5 (urease)
7,257 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Studies were conducted to evaluate the effect of overcooked soybean meals (SBM) on chick growth and amino acid availability. The SBM were custom-prepared at a commercial processing plant by changing the conditions of a desolventizer-toaster (DT) unit. Six progressively overcooked meals (designated SBM1 to 6 with SBM1 as normal, and SBM6 overcooked) were produced by increasing temperature by up to 50% and extending retention time by up to 75% above normal. The meals measured .05, .03, .01, .09, .00, and .00 delta pH of urease activity; 6.10, 5.01, 4.62, 4.83, 2.32, and 1.78 mg/g SBM of trypsin inhibitor activity; 92, 89, 91, 88, 81, and 81% of protein solubility in .2% KOH; and 46, 43, 41, 40, 23, and 19% of protein solubility in .1 M borate at 40 C, respectively. Glucose content in the hydrolysate of the soluble carbohydrate extract did not differ among the meals, indicating no differences in the degradation of sucrose, raffinose, and stachyose with increasing heat treatment. In a chick growth experiment with a methionine-adequate, low-protein diet, chicks fed SBM1 showed significantly greater weight gain than chicks fed SBM3, 5, or 6. The SBM1, 2, 5, and 6 were chosen for a study of amino acid availability. No differences were observed in amino acid content. There were significant differences in apparent amino acid availability to growing chicks, but not in true amino acid availability by adult roosters among the four meals. The results suggest that the temperature or the retention time of a DT unit may be increased by 50% over the usual operating conditions without reducing amino acid availability from SBM.
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PMID:Effect of overcooked soybean meal on chicken performance and amino acid availability. 156 Dec 16

An experiment was conducted with ileally cannulated pigs to determine the apparent digestibility of amino acids and N in raw or heated conventional or low-trypsin-inhibitor soybeans. Six littermate barrows initially averaging 24 kg were fed cornstarch-based diets (10.5% CP, .68% lysine, 3,558 kcal of ME/kg) supplemented with raw (unheated), conventional soybeans; raw, low-trypsin-inhibitor soybeans; heated, conventional soybeans; heated, low-trypsin-inhibitor soybeans; or solvent-extracted soybean meal. Heating was achieved by autoclaving soybeans (after grinding) for 20 min at 110 degrees C. The urease activities of the two raw soybean sources were similar, but the trypsin inhibitor activity of the raw, low-trypsin-inhibitor soybeans was about one-half that of the raw, conventional soybeans. The lower trypsin inhibitor activity of the raw, low-trypsin-inhibitor soybeans was associated with an improvement in the apparent digestibility of amino acids and N compared with the raw, conventional soybeans (P less than .05). Heating reduced the urease and trypsin inhibitor activities and improved (P less than .05) the apparent digestibility of amino acids and N in both types of soybeans. However, the heated, conventional soybeans contained more trypsin inhibitor activity than the heated, low-trypsin-inhibitor soybeans and the digestibilities of the amino acids were lower (P less than .05). Although the urease and trypsin inhibitor activities of the two heated soybean sources were similar to or less than those of soybean meal, the digestibilities of amino acids were not as great (P less than .05) in the heated soybeans as in soybean meal.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Apparent digestibility of amino acids in raw and heated conventional and low-trypsin-inhibitor soybeans for pigs. 156 6

Four soybean meals (SBM) were prepared in a commercial solvent-extraction plant to give a much wider range in heat treatment than is usually found among commercially available SBM. The meals were designated in ascending order of heat treatment as Under, Normal, Over and Rumen Escape. The Normal meal was processed using standard operating conditions. The Under meal received less heat treatment by reducing the steam pressure and retention time in the desolventizer-toaster. Over and Rumen Escape meals received further heat treatment in an additional four-compartment toaster. The Over meal received less heat treatment than the Rumen Escape meal by reducing steam pressure and retention time in both toasters. Crude protein content was similar for the four meals, but lysine tended to decrease with increasing heat treatment. In general, urease activity, trypsin inhibitor, protein dispersibility index and nitrogen solubility index decreased with increasing heat treatment. The +a Hunterlab color values increased as heat treatment increased. Apparent ileal digestibility of N and amino acids were similar for all meals (P greater than .05); however lysine digestibility for the Rumen Escape meal was 3.3 percentage units lower than the average of the lesser-heated meals. Energy digestibilities and nitrogen balance data were also similar (P greater than .05) for the four meals, but the apparent biological value of the Rumen Escape meal was 4.5 percentage units lower than the average of the other meals. There were no differences in nutritional value among the Under, Normal and Over meals, which represent the range in heat treatment usually found among SBM. The Rumen Escape meal, which received more severe heat treatment, tended to have lower nutritional value than the lesser-heated meals.
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PMID:Effects of different heat treatments during processing on nutrient digestibility of soybean meal in growing swine. 369 52

The effects of thermal treatment, dry heat and steam on the physiologically active substances: urease and trypsin inhibitors of soybean products, were evaluated by means of urease activity and trypsin inhibitor activity. The parameters time and temperature, moisture and particle size were considered. From these analyses it can be concluded that the best conditions to obtain optimum soybean products were 25% of initial moisture content, exposed to steam (97 degrees C) during four to eight minutes.
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PMID:[Selection of parameters for thermal treatment of soybeans by enzyme inactivation]. 383 74

Penicillin amidase, alpha-chymotrypsin and urease have been immobilized in water-soluble nonstoichiometric polyelectrolyte complexes (N-PEC). N-PEC are formed by modified poly(N-ethyl-4-vinyl-pyridinium bromide) (polycation) and excess poly(methylacrylic acid) (polyanion). N-PEC are a new class of polymers capable, characteristically, of phase transitions solution in equilibrium precipitate induced by slight change in pH or ionic strength. Neither the chemical structure of the carrier nor the number of cross-linkages between an enzyme and a carrier change on phase transition. That gives an unique opportunity to elucidate the difference between enzymes immobilized on water-soluble and water-insoluble supports. A detailed study of the phase transition effect on thermal stability of the enzymes and protein-protein interactions has been carried out. The following effects were found. Pronounced thermal stabilization of penicillin amidase and urease may be achieved on two conditions: the enzyme is in the precipitate; (b) the enzyme is linked to the N-PEC nucleus. Then the thermal stability of N-PEC-bound penicillin amidase increases 7-fold at pH 5.7, 60 degrees C, and 300-fold at pH 3.1, 25 degrees C, compared to the native enzyme. For urease, the thermal stabilization increases 20-fold at pH 5.0, 70 degrees C. The localization of enzyme on N-PEC has been established by titration of alpha-chymotrypsin bound to a polycation or polyanion with basic pancreatic trypsin inhibitor. Both in solution (pH 6.1) and in N-PEC precipitate (pH 5.7), an alpha-chymotrypsin molecule bound to a polyanion is fully exposed to the solution. If the enzyme is bound to a polycation, only 20% of alpha-chymotrypsin molecules in the precipitate and 40% in solution retain their ability for protein-protein interactions. This means that a polycation-bound enzyme is localized in the hydrophobic nucleus of the complex, whereas the polyanion-bound enzyme sits on the hydrophilic shell of the complex. On pH-induced phase transition (pH decreases from 6.1 to 5.7), there occurs a stepwise decrease in penicillin amidase activity which is due to a 9.8-fold increase in the Km for 2-nitro-4-phenylacetamidobenzoic acid. Change of the catalytic activity and thermal stability of N-PEC-bound penicillin amidase is fully reversible and reproducible. Such soluble-insoluble immobilized enzymes with controllable thermal stability and activity may be used for simulating events in vivo and in biotechnology.
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PMID:Enzymes in polyelectrolyte complexes. The effect of phase transition on thermal stability. 397 68

The objectives were to determine the responses of turkeys to soybean meals (SBM) differing in urease and trypsin inhibitor activity, to estimate the AME of diets containing these SBM, and to determine the responses to supplemental L-Met and L-Lys. Four experiments were conducted with poults 1 to 3 wk of age and one with turkeys 6 to 8 wk of age. In Experiment 1, the trypsin inhibitor activities (TI) were 1.8, 4.2, 5.4, 7.0, and 8.8 mg trypsin inhibited/g SBM (method of Hamerstrand et al., 1981). The corresponding urease indices were .02, .14, .51, .90, and 1.5 pH units. The SBM were 46% of the diet. Significant pancreatic hypertrophy occurred with dietary concentrations of TI of 3.2 mg/g and above. At 4.0 mg TI/g of diet, the feed:gain ratio was increased, but body weight gain and AME of the diet were reduced. In Experiments 2, 3, and 4, poults responded similarly to Met additions to diets containing 46% SBM with TI of 1.8 or 4 mg/g SBM, or to Met or Met plus Lys additions to diets containing 40.7 or 49.6% SBM with TI of 2 or 11 mg/g SBM. In Experiment 5, the SBM contained TI at 4.3, 6.1, 8.9, or 12.5 mg/g. The corresponding urease indices were .05, .27, 1.43, and 1.72 pH units. The SBM were 49.6% of the diet. Using 6 to 8 wk old turkeys, the AME of the four diets were determined to be 2.76, 2.71, 2.58, and 2.57 Mcal/kg. The AME of diets containing 4.4 and 6.2 mg TI/g of diet were reduced (P < .05). In conclusion, through 3 wk of age, turkeys can tolerate soybean TI concentrations of 2.5 mg TI/g of diet. Turkeys 6 to 8 wk of age can tolerate 3 mg of soybean TI/g of diet.
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PMID:Tolerance of turkeys to diets high in trypsin inhibitor activity from undertoasted soybean meals. 747 89

The fluidised bed drying characteristics of soybeans at high temperatures (110-140 degrees C) and moisture contents, 31-49% dry basis, were modelled using drying equations from the literature. Air speeds of 2.4-4.1 m/s and bed depths from 10 to 15 cm were used. The minimum fluidised bed velocity was 1.9 m/s. From a quality point of view, fluidised bed drying was found to reduce the level of urease activity which is an indirect measure of trypsin inhibitor, with 120 degrees C being the minimum required to reduce the urease activity to an acceptable level. Increased air temperatures caused increased cracking and breakage, with temperatures below 140 degrees C giving an acceptable level for the animal feed industry in Thailand. The protein level was not significantly reduced in this temperature range. The drying rate equations and quality models were then combined to develop optimum strategies for fluidised bed drying, based on quality criteria, drying capacity, energy consumption and drying cost. The results showed that from 33.3% dry basis, soybean should not be dried below 23.5% dry basis in the fluidised bed dryer, to avoid excessive grain cracking. The optimum conditions for minimum cost, minimum energy and maximum capacity coincided at a drying temperature of 140 degrees C, bed depth of 18 cm, air velocity of 2.9 m/s and fraction of air recirculated of 0.9. These conditions resulted in 27% cracking, 1.7% breakage and an energy consumption of 6.8 MJ/kg water evaporated.
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PMID:Fluidised bed drying of soybeans. 1112 77

The research was conducted with two different recently released Brazilian soybean cultivars (Rio Balsas and Bays) to evaluate whether there is any correlation between the different levels of antinutritional and/or toxic proteins in the cultivars and their nutritive value as sources of protein for monogastric animals (rats). Furthermore, it is discussed, for the first time, the role of the dietary soyatoxin on the performance of rats fed on diets containing soyatoxin-rich (cv. Bays) and soyatoxin-free (cv. Rio Balsas) soybean cultivars. Feeding rats with diets containing raw soybean cultivars showed a lower growth rate, net protein utilization and digestibility, a much higher dry matter and nitrogen excretion and macroscopic alterations in internal organs when compared to rats fed on egg-white protein. The nutritional parameters measured for the diet based on raw Bays cultivar were poorer than those of the diet prepared with Rio Balsas. In the raw soybeans, trypsin inhibitor and lectin, and urease to a lesser extent, significantly affected at different fashion the soybean protein utilization. Heating treatment of the Bays seeds increased the growth rate, NPU, in vivo protein digestibility and practically eliminated or attenuated all the organ alterations observed. This study might be helpful in the choice of safe and nutritious soybean cultivars.
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PMID:Nutritional study of two Brazilian soybean (Glycine max) cultivars differing in the contents of antinutritional and toxic proteins. 1117 62

Native soybean lectins (SBL) could potentially have deleterious effects on young animals. The objectives of this study were to determine the optimum processing temperature and time at which SBL is inactivated and to investigate the possibility of using urease activity (UA) to predict residual lectin levels in soybean meal (SBM). Raw defatted SBM was steam-heated at incremental temperatures between 90 and 120 degrees C for 5 to 20 min in an autoclave. The processed meals were subjected to native-PAGE and measurement of total carbohydrate-binding lectin (TCBL), agglutinating lectin (AL), UA, and trypsin inhibitor (TI). Processing severity was evaluated by determining protein solubility in 0.2% potassium hydroxide. Results indicated that levels of all antinutrients (TCBL, AL, UA, and TI) decreased with increasing processing temperature (P < 0.05). The intensity of the lectin band on the electrophoresis gel was considerably reduced when meal was heated at 100 degrees C for 5 min. This result implied that lectin inactivation occurred at 100 degrees C. More than 90% of all the original antinutrient levels in the raw meal were destroyed when meals were heated at 100 degrees C for 5 min. Meals processed at 100 degrees C for 5 to 20 min had protein solubility values (80 to 85%) indicative of adequate processing. The denaturation pattern of UA was highly correlated with that of SBL (r > or = 0.73), indicating that UA could be used for monitoring lectin levels in commercial meals. We concluded that UA of 0.03 to 0.09 units of pH change are indicative of adequately processed meals that contain negligible lectin levels.
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PMID:Investigating the possibility of monitoring lectin levels in commercial soybean meals intended for poultry feeding using steam-heated soybean meal as a model. 1271 Apr 87

Nutrient composition, ileal amino acid (AA) digestibility, and AME of 55 soybean meal (SBM) samples from the United States (US; n = 16), Argentina (ARG; n = 16), Brazil (BRA; n = 10), and India (IND; n = 13), collected from commercial mills in Southeast Asia, were compared using laboratory analyses and animal studies. There were significant (P < 0.05 to 0.001) differences due to origin in CP, fat, ash, fiber, and nonstarch polysaccharide (NSP) contents of SBM. The average CP content of US, ARG, BRA, and IND samples was determined to be 47.3, 46.9, 48.2, and 46.4% (as-fed basis), respectively. Compared with SBM from other origins, crude fiber and NSP contents were lower (P < 0.05) and sucrose content was higher (P < 0.05) in the US samples. The IND samples had the highest (P < 0.05) contents of fiber, ash, and NSP, and lowest (P < 0.05) contents of fat and sucrose. Differences (P < 0.0001) were observed among origins for in vitro protein quality measures (urease index, KOH protein solubility, and trypsin inhibitor activity). Significant (P < 0.001) effects due to origin were observed for all minerals. Soybean meal from the US and IND had higher (P < 0.05) calcium contents (0.45%) compared with those from ARG and BRA (0.28-0.31%). Phosphorus and potassium contents were lowest (P < 0.05) in SBM from IND, and no differences (P > 0.05) were observed in SBM from other origins. Iron content was markedly high (928 mg/kg) in SBM from IND compared with those from other origins (103-134 mg/kg). Major origin-related differences (P < 0.0001) were observed in the AME of SBM. The average AME content of US, ARG, BRA, and IND samples was 2,375, 2,227, 2,317, and 2,000 kcal/kg (as-fed basis), respectively. Total AA contents of US, ARG, BRA, and IND samples were similar (P > 0.05) for 9 of the 17 amino acids. Major differences (P < 0.05 to P < 0.001) due to origin were determined for the digestibility of all AA. The IND samples had the lowest (P < 0.05) digestibility and no differences (P > 0.05) between samples from other 3 origins. However, the digestible CP content of US SBM was higher (P < 0.05) than those of ARG and IND, but similar (P > 0.05) to that from BRA. The digestible CP contents of SBM from the US, ARG, BRA, and IND were 40.0, 38.6, 39.8, and 36.7%, respectively. Digestible contents of indispensable AA, in general, followed the same trend as that of digestible CP. In conclusion, the present evaluation showed that major differences in nutritive value do exist between SBM from different origins in terms of nutrient contents, AME, and digestible AA. Overall, SBM originating from the US had better nutritive value compared with those from ARG and IND, on the basis of AME and contents of digestible CP and digestible AA.
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PMID:Nutrient analysis, metabolizable energy, and digestible amino acids of soybean meals of different origins for broilers. 2512 60


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