Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.3.5.5 (CPS)
 1,262 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Studies were carried out to determine the distribution of the following: (1) carbamoyl phosphate synthetase (EC 2.7.2.9), (2) ornithine carbamoyltransferase (EC 2.1.3.3), (3) argininosuccinate synthetase (EC 6.3.4.5), and (4) argininosuccinate lyase (EC 4.3.2.1) in soybean cells grown in suspension culture. Protoplasts were produced from the soybean cells by treatment with cellulase (EC 3.2.1.4) and pectinase (EC 3.2.1.15); the protoplasts were then ruptured by osmotic shock with distilled water. This treatment was followed by differential centrifugation and sucrose density gradient centrifugation to isolate various organelle fractions including mitochondria and plastids. Examination of these fractions using specific enzyme assays showed that carbamoylphosphate synthetase and ornithine carbamoyltransferase were localized in a fraction found to be composed primarily of plastids. Argininosuccinate synthetase and argininosuccinate lyase appeared to be associated with either the cytosol or a membrane fraction in close association with the cytosol such as the endoplasmic reticulum or protoplast membrane.
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PMID:The localization within plant cells of enzymes involved in arginine biosynthesis. 56 67

The changes of carbamyl phosphate synthetase I (CPS 1) in diethylnitrosamine-(DEN)-induced enzyme-altered liver cells were studied by means of immunohistochemical (PAP) and in situ cDNA-mRNA hybridization methods. The experimental rats were treated with DEN, 2-acetylaminofluorene (2-AAF) and 2/3 hepatectomy according to Solt-Farber's protocol and were further promoted by oral daily administration of 0.05% phenobarbital in drinking water. The results showed that the average number of lesions showing abnormal expression of CPS 1 was relatively constant over the course of the experiment (8 months), while the number of normally expressing lesions gradually decreased. The former lesions were also larger in volume than the latter ones. We conclude that in DEN-initiated lesions the abnormally expressed CPS 1 lesions may grow continuously, thus leading to the formation of larger nodules. We also suspect that some of these lesions have increased tendencies to develop into tumors.
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PMID:The immunohistochemistry and in situ cDNA-mRNA hybridization of carbamyl phosphate synthetase I in enzyme-altered liver cells during carcinogenesis. 237 Dec 60

Different fixation media have been compared in order to find one that preserves the histological structure of rat liver and allows unambiguous immunohistochemical detection of carbamoyl-phosphate synthetase (ammonia). Fixation of rat liver in a mixture of methanol, acetone, and water yields the most intense immunohistochemical staining. Using a specific antiserum raised against rat liver carbamoyl-phosphate synthetase, less than 1% of the enzyme protein is extractable after this fixation procedure, and the histological structure is similar to that after fixation in Bouin's fixative. Specific immunohistochemical staining is localized exclusively in the cytoplasm of the parenchymal cells; its granular distribution is in accordance with the mitochondrial localization of carbamoyl-phosphate synthetase. Immunohistochemical staining shows a heterogeneous distribution within the liver acinus. Staining is most intense around the portal venules, decreases slowly toward the hepatic venules and is, after an abrupt decrease, virtually absent in a limited area surrounding these venules. The possible significance of the heterogeneous distribution of carbamoyl-phosphate synthetase for ammonia metabolism is discussed.
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PMID:Immunohistochemical localization of carbamoyl-phosphate synthetase (ammonia) in adult rat liver; evidence for a heterogeneous distribution. 637 12

Changes in urea synthesis in the liver of rats treated with 32% ethanol in the drinking water for up to 6 months were studied using perfused livers, isolated hepatocytes, and mitochondria. Results obtained from ethanol-treated rats are summarized as follows: (1) the mitochondria of the hepatocytes of rats treated with ethanol for 2 months or longer became enlarged to various degrees, (2) the levels of ammonia in the serum remained within a normal range, while those in liver tissue were elevated compared with the control, (3) urea synthesis from ammonia in perfused livers was decreased markedly, while that from citrulline remained in the normal range, (4) the activities of carbamyl phosphate synthetase (CPS; EC 2.7.2.5) and ornithine transcarbamylase (OTC; EC 2.1.3.3) in mitochondria were unchanged compared with those of the control, and (5) the levels of ATP in liver tissue and the ability of mitochondria to synthesize ATP were decreased markedly compared with the control. Both the level of ATP in the hepatocytes and the synthesis of urea from ammonia by perfused livers of rats treated with ethanol were resistant to externally added ethanol, while those of control animals were severely affected. These results suggest that the intracellular level of ATP is intimately related to urea synthesis in both control and ethanol-treated animals, and lowered levels of ATP may be a key factor in the suppression of urea synthesis in ethanol-treated animals.
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PMID:Studies on urea synthesis in the liver of rats treated chronically with ethanol using perfused livers, isolated hepatocytes, and mitochondria. 750 89

The solution properties of the capsular polysaccharide produced by Klebsiella pneumoniae SK1, SK1-CPS, were investigated by various methods. The SK1-CPS repeating unit is a branched pentasaccharide containing one glucuronic acid as single unit side chain; acetyl groups are present as non-carbohydrate substituents on the uronic acid residue in non-stoichiometric amounts. Chiro-optical, potentiometric, viscometric and rheological measurements have been performed in order to characterize the conformational behaviour of the polymer in water and in aqueous salt solutions. Under the investigated experimental conditions, changes of temperature, ionic strength and pH were shown not to induce any cooperative conformational transition. All the results obtained suggest that the solution conformation of SK1-CPS is a random coil with a certain degree of chain flexibility. The removal of the acetyl substituents apparently does not modify the overall conclusions drawn for the native polymer, except for an incipient tendency to aggregation revealed for high salt conditions.
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PMID:Solution properties of the capsular polysaccharide produced by Klebsiella pneumoniae SK1. 837 38

This study evaluated the shear bond strength to enamel and dentin and bonding mechanism to dentin of Gluma CPS bonding system to primary teeth enamel and dentin. Pekafill hybrid composite was used. Ten specimens were immersed in deionized water at 37 degrees C for twenty-four hours and ten other specimens were subjected to a thermocycling procedure (2000 cycles between 5 degrees and 55 degrees C, dwell time fifteen seconds). After water storage or thermocycling, the bonded cylinders were sheared and the bond strength calculated. After debonding, the failure sites of all samples were evaluated microscopically. The data were analyzed with an ANOVA and Student-Newman-Keuls test. In ten other primary molars, the buccal surfaces were ground flat on wet SiC papers to expose peripheral dentin. Cylindrical buttjoint cavities were prepared with a cylindrical diamond bur. The cavities were treated with Gluma CPS and filled with pekafill as described above. After fifteen-minute water storage, filling excess was removed and marginal integrity and bonding mechanism of five restorations was examined with a light microscope. Five other restorations were evaluated after storage in water at 37 degrees C for twenty-four hours. Maximal gap widths and hybrid layer thickness were determined. The results showed that thermocycling did not affect the shear bond strength to enamel or dentin. There was a statistically significant difference (p < 0.05) between the shear bond strength values obtained in enamel and dentin. The maximal gap width was not significantly different between specimens that were stored in water for fifteen minutes or twenty-four hours. The average hybrid layer thickness was 11.7 +/- 1.1 micrograms. All specimens revealed a resin cohesive failure very close to enamel or dentin surface. The etch patterns produced on the abraded enamel surface were uniform and deeper as compared to the sample that was pumiced. This was also confirmed in the epoxy replicas.
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PMID:Enamel and dentin bond strength and bonding mechanism to dentin of Gluma CPS to primary teeth. 909 16

Low levels of all of the enzymes required for urea synthesis via the urea cycle, including mitochondrial glutamine- and acetylglutamate-dependent carbamoyl-phosphate synthetase III (CPSase III) and cytosolic glutamine synthetase, are known to be present in liver of the teleost fish largemouth bass (Micropterus salmoides). The levels of these enzymes are higher than those in most other teleosts, but they are significantly lower than the levels present in liver of ureoosmotic elasmobranchs. The purpose of this study was to assess the physiological role of CPSase III in the context of urea synthesis in adult bass. The results showed that urea-N accounts for about 30% of the total nitrogen (ammonia-N plus urea-N) excreted under control conditions. The rate of urea-N excretion did not increase in response to exposure to 1 mM NH4Cl (3 days) or 0.25 mM NH4Cl (12 days) in the external water, except for a transient increase after a day or two of exposure. CPSase III activity in liver also did not increase in response to exposure to ammonia. Adult largemouth bass, while apparently ureogenic, are primarily ammonotelic and remain so even in the presence of relatively high concentrations of ammonia in the external environment. The total units of CPSase III activity in liver are not sufficient to account for the quantity of urea that is excreted. However, CPSase III and ornithine carbamoyltransferase (OCTase) activities were found to be present in intestinal tissue and, unexpectedly, in muscle tissue. The total units of CPSase III and OCTase in muscle, intestine, and liver appear to be sufficient to account for the observed rate of urea excretion. The sequence of CPSase III cDNA was determined, which permitted the use of ribonuclease protection assays to demonstrate the presence of CPSase III mRNA in these tissues.
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PMID:Nitrogen excretion and expression of carbamoyl-phosphate synthetase III activity and mRNA in extrahepatic tissues of largemouth bass (Micropterus salmoides). 947 89

Surgical implant finishing and sterilization procedures were investigated to determine surface characteristics of unalloyed titanium (Ti). All specimens initially were cleaned with phosphoric acid and divided into five groups for comparisons of different surface treatments (C = cleaned as above, no further treatment; CP = C and passivated in nitric acid; CPS = CP and dry-heat sterilized; CPSS = CPS and resterilized; CS = C and dry-heat sterilized). Auger (AES), X-ray photoelectron (XPS), and Raman spectroscopic methods were used to examine surface compositions. The surface oxides formed by all treatments primarily were TiO2, with some Ti2O3 and possibly TiO. Significant concentrations of carbonaceous substances also were observed. The cleaning procedure alone resulted in residual phosphorus, primarily as phosphate groups along with some hydrogen phosphates. A higher percentage of physisorbed water appeared to be associated with the phosphorus. Passivation (with HNO3) alone removed phosphorus from the surface; specimens sterilized without prior passivation showed the thickest oxide and phosphorus profiles, suggesting that passivation alters the oxide characteristics either directly by altering the oxide structure or indirectly by removing moieties that alter the oxide. Raman spectroscopy showed no crystalline order in the oxide. Carbon, oxygen, phosphorus, and nitrogen presence were found to correlate with previously determined surface energy.
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PMID:Effect of surface treatment on unalloyed titanium implants: spectroscopic analyses. 959 42

Precision UV(TM) contact lenses were photoaged beyond their expected lifetime in an accelerated manner with a SUNTEST(R) CPS(+) system, which is a solar spectrum equivalent. Ultraviolet spectra of lenses irradiated for 30 h in saline at 41 degrees C and 44 degrees C at the highest power setting were statistically indistinguishable from those measured prior to the exposure. In a similar experiment run at 79 degrees C, the UVB range of the spectra showed small but statistically significant differences, whereas the UVA range of the spectra were not distinguishable. Lenses photoaged at half power and twice the time at 43 degrees C gave UV spectra that could be distinguished. Refractive indices of lenses were indistinguishable before and after irradiation. Eluted materials could not be detected in the saline used to maintain lenses in any irradiation experiment. Lens parameters and water contents remained within manufacturing specifications before and after irradiation.
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PMID:Accelerated photostability testing of precision UV(TM) contact lenses. 1086 33

Bostrichthys sinensis inhabits brackish water, living in the crevices of the river mouths of Shang Xi and Guangdong, China. In its natural habitat, it may encounter aerial exposure frequently during low tides, and it usually remains quiescent in the absence of water. Upon aerial exposure in the laboratory, the ammonia excretion rate decreased to one-fourth that of the submerged control. Although all the enzymes of the ornithine-urea cycle were detected in the liver of this fish, the activity of hepatic carbamoyl phosphate synthetase was too low for the cycle to be functioning. Indeed, ammonia accumulated in the tissues and was not converted to urea. Results indicate that ammonia produced through amino acid catabolism was detoxified to glutamine during the first 24 h of aerial exposure. The excess amount of glutamine stored in the muscle during this period couldaccount approximately for the reduction in ammonia equivalent excreted. There was indeed a significant increase in the activity of glutamine synthetase from the liver of specimens exposed to terrestrial conditions. In contrast to the production of alanine, formation of glutamine is energetically expensive. Since B. sinensis remained relatively inactive on land, the reduction in energy demand for muscular activity might provide it with the opportunity to exploit glutamine formation as a means to detoxify ammonia. After 72 h of aerial exposure, B. sinensis reduced internal ammonia production, possibly through reductions in proteolysis and amino acid catabolism, to avoid excessive accumulation of ammonia.
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PMID:The sleeper Bostrichthys sinensis (family Eleotridae) stores glutamine and reduces ammonia production during aerial exposure. 1149 23


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