Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.2.1.1 (ACS)
 78,556 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The synthesis of a new coenzyme A analogue, N6-[N-(6-aminohexyl)carbamoylmethyl]-CoA, suitable for immobilisation through its terminal amino group to support matrices, is described. The synthetic route starts with bis(CoA) and involves the following steps: alkylation with iodoacetic acid and rearrangement yielding bis(N6-carboxymethyl-CoA), elongation of the carboxymethyl terminal with 1,6-diaminohexane using carbodiimide to yield bis(N6-[N-(6-aminohexyl)-carbamoylmethyl]-CoA) and finally the splitting of this bis[CoA analogue) through reduction with dithiothreitol to give the final product in approximately 10% overall yield. This CoA analogue showed 'coenzymic activity' with the enzymes acetyl-CoA synthetase, phosphotransacetylase and succinic thiokinase. Covalent binding of the CoA analogue to Sepharose 4B was normally carried out using its S-(5-thio-2-nitrobenzoic acid) derivative as this allows a convenient way for determining the amount of ligand coupled, based on the amount of 5-thio-2-nitrobenzoic acid liberated from the gel after reduction with dithiothreitol. After covalent binding of the CoA analogue to water-soluble activated dextran 70, the analogue was recycled while present in an ultrafiltration cell using the enzymes phosphotransacetylase and citrate synthase. The reaction was followed by measuring the citrate formed on addition of acetylphosphate and oxaloacetate. In affinity chromatographic studies it was shown that the CoA-Sepharose preparation could bind the CoA-dependent enzymes citrate synthase and succinic thiokinase and these could be biospecifically eluted using soluble CoA.
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PMID:N6-[N-(6-Aminohexyl)carbamoylmethyl]-coenzyme A. Synthesis and application in affinity chromatography and as an immobilized active coenzyme. 57 88

We hypothesized that sources of activated charcoal (AC) used as a form of gut decontamination in the treatment of drug overdose may deliver significantly less charcoal than expected because of retained charcoal and sorbitol (ACS) from the treatment of 50 consecutive overdose patients were collected. Health care personnel delivering the dose were unaware of the study hypothesis. A total of 82 containers were obtained in this manner. Each container was labelled to contain 25 g AC and 48 g sorbitol. Five unused containers of ACS were obtained as controls. Each container was thoroughly cleaned, and the contents vacuum filtered and washed with 1 L of tap water. The tared filter paper and charcoal was dried for 24 h and weighed. The average amount of charcoal retained in each used container (retained) was 0.549 g (range 0.318-1.637 g). This accounts for 2.2% of the 25 g dose expected to be delivered. The average amount of charcoal found in each unused container (actual) was 25.892 g. The delivered dose (actual minus retained) may be calculated as 101.4% of the expected 25 g dose. When using this formulation of ACS there is no significant difference between the amount of charcoal given to an overdose patient and the amount ordered for gut decontamination. Despite the poor suspension of charcoal in sorbitol and the less than ideal conditions under which it is given, the patient receives an adequate dosage of AC if it is ordered.
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PMID:Container residue after activated charcoal administration in the emergency department. 162 55

alpha, beta-Unsaturated coenzyme A (CoA) thioesters including acrylyl CoA, methacrylyl CoA, and propiolyl CoA were synthesized by catalysis with acetyl CoA synthetase (EC 6.2.1.1.). After isolation from the enzymatic reactions, the products were found to be the result of 1,4 addition of CoASH to the double bond and addition of water to the triple bond of the initial acyl CoA adducts. Structural determinations of these products by 1H NMR, 13C NMR, and the chemical reactions leading to their formation are described.
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PMID:Acetyl coenzyme A synthetase catalyzed reactions of coenzyme A with alpha, beta-unsaturated carboxylic acids. 289 6

The paper discusses the results of a study of the case histories of 90 cancer patients. 48 of these patients received a course of treatment including physical rehabilitative therapy, dietotherapy, mesenchemotherapy (fractionated doses of ACS Bogomoletz, zymosan, splenin), oxygen and iodine-bromine baths, mineralized water and non-specific medication (vitamins, ext. eleutherococci, methonine, cholenzyme) and psychotherapy. It is suggested that non-specific therapy generally provided at health resort establishments is indicated in radically-operated stomach and breast cancer patients who reveal no signs of recurrence or metastases. Such therapy may contribute to social and occupational rehabilitation of cancer patients.
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PMID:[Experience in rehabilitating cancer patients at sanatoria and health resorts]. 710 34

Separation of the ammonium sulfate precipitated protein fraction of mouse ascitic fluid, containing the specific immunoglobulin (pI 6.7-6.8; molecular weight 180000), from ammonium sulfate was investigated by means of non-traditional dialysis, based on the difference in diffusion rates of small and large molecules through porous membranes. The experiments were carried out in spiral membrane modules equipped with a Neosepta (AM-2 or ACS-SB) anion exchange membrane and a microfiltration membrane (Synpore or Sartorius). To enhance the driving force for penetration of ammonium sulfate and low-molecular-weight components from solution of ascitic protein fraction into water, a counterpressure was imposed on the side of microfiltration membrane. The flow rate, counterpressure and the pore sizes of microfiltration membranes had a significant effect on the separation process, as expected. The type of the anion exchange membrane had only a small effect. This process makes it possible to desalt the immunoglobulin fraction with high purity and yield in a few hours instead of 5 days.
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PMID:Separation of specific immunoglobulin. 1. Desalination using a membrane system. 776 50

Enzymes subjected to freeze-thawing are known to be protected by polymers that are preferentially excluded from the hydrated surface of proteins [reviewed in Carpenter et al. (1994) ACS Symp. Ser. 567, 134-147]. Preferentially excluded solutes are also known to stabilize quaternary structure, which enhances the thermostability of multimeric proteins in aqueous systems. Also, it has been suggested that retention of quaternary structure may play a role in the protection of multimeric proteins by polymers during freeze-drying (lyophilization). Although preferential solute exclusion cannot occur in the absence of water, we reasoned that polymers could protect multimeric proteins during freeze-drying by stabilizing quaternary structure in the frozen state. Our results are consistent with this hypothesis and demonstrate that bovine serum albumin and polyvinylpyrrolidone stabilize lactate dehydrogenase by inhibiting dissociation in the frozen solution, during the initial phase of the sublimation step of lyophilization. Dissociation at this critical step correlated directly with decreased recovery of enzyme activity after rehydration. The damage to the protein, under conditions where dissociation was studied, was due to a large decrease in pH in the frozen state (e.g., from pH 7.5 to 4.5), which was attenuated by protective levels of polymers. Thus, inhibition of freezing-induced pH shifts, in addition to stabilization by the preferential exclusion mechanism, plays an important role in the protection conferred by polymers. Furthermore, high concentrations of these polymers were capable of maintaining quaternary structure during subsequent drying and rehydration. We suggest that the proximate cause for increased recovery of active, native protein after lyophilization is that the holoenzyme is more resistant to the stresses of drying/rehydration than unassociated monomers.
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PMID:Polymers protect lactate dehydrogenase during freeze-drying by inhibiting dissociation in the frozen state. 880 30

In a multicenter study including 5 dialysis units, blood acetate changes during 4 h dialysis sessions in 141 patients treated with a 4 mM acetate-containing bicarbonate dialysate (ABD) were evaluated and compared to the values of 114 patients using an acetate-free bicarbonate dialysate (AFD). Acetate-free bicarbonate dialysate was delivered by a dialysis machine from the mixing with water for dialysis of a 1/26.2 bicarbonate concentrate, and a 1/35 acid-concentrate in which acetic acid was substituted for hydrochloric acid (Soludia, Fourquevaux, France). This new type of dialysate was routinely in use for 3 years on average (range, from 2 to 5 years). All patients fasted before and during dialysis. Blood samples were withdrawn at the start and at the end of dialysis sessions. The acetate plasma concentration was determined using the acetyl-CoA synthetase enzymatic method (Boehringer, Manheim, Germany). In patients treated with ABD whose predialysis blood acetate levels were in the physiologic range of < or = 100 microM (n = 113), the acetate plasma concentration increased from a predialysis mean value of 22+/-3 microM to a postdialysis mean value of 222+/-11 microM in 88 patients (78% of patients) whereas the acetate plasma concentration changes remained in the range of physiologic values from 21+/-6 to 58+/-7 microM in the other 25 patients. In contrast, patients treated with AFD whose predialysis blood acetate levels were in the physiologic range (n = 108), acetate plasma concentration increased from a predialysis mean value of 49+/-6 microM to 160+/-19 microM in only 13 patients (12% of patients) whereas acetate plasma concentration changes remained in the range of physiologic values of 23+/-2 to 41+/-3 microM in most of the patients of this group. In this study, a significant number of patients, whether receiving standard or acetate-free bicarbonate dialysates, exhibited an extremely high acetate plasma concentration at the start of the dialysis session. Hyperacetatemia was controlled with AFD in patients whose predialysis acetate plasma concentration of 316+/-82 decreased to 55 +/-23 microM (n = 6) at the end of the dialysis session whereas the acetate plasma concentration remained high when the predialysis concentration was 580+/-76 microM, with a postdialysis concentration of 233+/-39 microM (n = 28). It is concluded that in patients whose predialysis blood acetate levels were in the physiologic range, acetate-containing bicarbonate dialysate induces hyperacetatemia whereas postdialysis blood acetate remains in the normal range in such dialysis patients treated with acetate-free dialysate. Chronic hyperacetatemia, which could be found in dialysis patients, is well controlled by dialysis using an acetate-free dialysate.
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PMID:Substitution of acetic acid for hydrochloric acid in the bicarbonate buffered dialysate. 968

Asian medicines are widely used as alternative medicine. However, interactions between drugs and Asian medicines have been poorly studied. Chan Su and Lu-Shen-Wan are Asian medicines that contain the cardiaoactive compound bufalin. Bufalin is structurally similar to digitoxin and is also strongly bound to serum albumin. The authors studied possible displacement of digitoxin from the protein binding site by bufalin. The authors prepared three serum pools from patients taking digitoxin and supplemented aliquots of each serum pool with no bufalin (control) and 25 ng/mL, 50 ng/mL, 100 ng/mL, 250 ng/mL, 500 ng/mL, and 1000 ng/mL bufalin. The authors observed significant displacement of digitoxin by bufalin as evidenced by increased free digitoxin concentrations. For example, the concentration of free digitoxin increased from a control value of 1.6 ng/mL to 2.5 ng/mL in the presence of 1000 ng/mL bufalin (total digitoxin: 36.3 ng/mL) in the serum pool 1. The authors observed similar increases in free digitoxin concentrations in other serum pools in the presence of various concentrations of bufalin. The authors used a chemiluminescent assay and ACS:180 analyzer to measure both total (in the original serum) and free (in the protein-free ultrafiltrate) digitoxin concentrations because the chemiluminescent assay does not cross-react with bufalin. When an acetone/water (1:1 by volume) extract of Chan Su was added to a serum pool containing digitoxin, the authors observed a significantly increased free digitoxin concentration, indicating that Chan Su can displace digitoxin from the protein binding site in vitro. The authors conclude that bufalin and acetone/water extract of Chan Su can cause significant displacement of digitoxin from the protein binding site.
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PMID:Interactions between drugs and Asian medicine: displacement of digitoxin from protein binding site by bufalin, the constituent of Chinese medicines Chan Su and Lu-Shen-Wan. 1077 25

Correct interpretation of 1H magnetic resonance (MR) studies of the red vertebral bone marrow in patients with disorders of the hematopoietic system requires knowledge of the dependence of the proton spectrum on age and sex. Infiltration of malignant cells causes a decreased red bone marrow fat signal, which is reversed upon successful treatment. The aim of this study was to establish a database of normal water/fat relations from a large group of volunteers. In all, 154 healthy volunteers from 11 to 95 years of age were examined using a 1.5-T MR system (ACS-NT, Philips). A volume of 2-8 ml in the center of a normal vertebral body was selected for spectroscopy using the PRESS sequence without water suppression (TR/TE 2 sec/40 msec). Signal intensities and T2 times of lipid and water resonances were determined. The relative fat signal intensity was calculated corrected for T2 relaxation. The relative proportion of protons in the fat signal increases with age from 24% in the age group 11-20 years to 54% in the group > or = 61 years. The proportion of fat in the vertebral bone marrow in female subjects is less than that in male subjects in the same age group (statistically significant at P < or = 0.01). In the central age group between 31 and 50 years, the difference is largest, at 12%; in the youngest and oldest age group this difference is small. T2 times are neither age nor sex dependent.
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PMID:Age- and sex-specific differences in the 1H-spectrum of vertebral bone marrow. 1116 33

The pathway of the oxidation of propionate to pyruvate in Escherichia coli involves five enzymes, only two of which, methylcitrate synthase and 2-methylisocitrate lyase, have been thoroughly characterized. Here we report that the isomerization of (2S,3S)-methylcitrate to (2R,3S)-2-methylisocitrate requires a novel enzyme, methylcitrate dehydratase (PrpD), and the well-known enzyme, aconitase (AcnB), of the tricarboxylic acid cycle. AcnB was purified as 2-methylaconitate hydratase from E. coli cells grown on propionate and identified by its N-terminus. The enzyme has an apparent Km of 210 micro m for (2R,3S)-2-methylisocitrate but shows no activity with (2S,3S)-methylcitrate. On the other hand, PrpD is specific for (2S,3S)-methylcitrate (Km = 440 micro m) and catalyses in addition only the hydration of cis-aconitate at a rate that is five times lower. The product of the dehydration of enzymatically synthesized (2S,3S)-methylcitrate was designated cis-2-methylaconitate because of its ability to form a cyclic anhydride at low pH. Hence, PrpD catalyses an unusual syn elimination, whereas the addition of water to cis-2-methylaconitate occurs in the usual anti manner. The different stereochemistries of the elimination and addition of water may be the reason for the requirement for the novel methylcitrate dehydratase (PrpD), the sequence of which seems not to be related to any other enzyme of known function. Northern-blot experiments showed expression of acnB under all conditions tested, whereas the RNA of enzymes of the prp operon (PrpE, a propionyl-CoA synthetase, and PrpD) was exclusively present during growth on propionate. 2D gel electrophoresis showed the production of all proteins encoded by the prp operon during growth on propionate as sole carbon and energy source, except PrpE, which seems to be replaced by acetyl-CoA synthetase. This is in good agreement with investigations on Salmonella enterica LT2, in which disruption of the prpE gene showed no visible phenotype.
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PMID:Oxidation of propionate to pyruvate in Escherichia coli. Involvement of methylcitrate dehydratase and aconitase. 1247 14


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