Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.11.18 (MAP)
 7,412 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phosphorus plays an essential role in cellular metabolism, especially in the oxidative phosphorylation process and in the synthesis of 2-3 DPG and membrane phospholipids. Moreover phosphorus is necessary as a buffer, mainly when the organism's principal buffer, the H2CO3/HCO3- system, is working at maximal rate. The authors describe a case of severe hypophosphatemia in a ICU patient with a mixed disorder of the acid-base balance. C.P., a woman, aged 71, obese (IBW 145%), at admission in ICU showed increasing dyspnea, hypoxemia and acidosis. Besides alkaline drugs a Venturi mask with FiO2 = 0.3 alternated to CPAP cycles (7 cm H2O) with facial mask applied. Bading on CVP, MAP and ABG results, a pharmacologic therapy with enoximone, furosemide, bronchodilators, mucolytics, antacids, antibiotics and inotropics was performed. TPN with only essential amino acids was performed, in order to activate lipolysis and ketogenesis; but the ABG showed over again mixed disorder of acid-base balance (metabolic and chronic respiratory acidosis), only partially leading to ketogenesis. The reduction of the hematic HCO3-, without changes of PaCO2, was justified by the blood lactic acid of 6.2 mmol/L. And what about blood lactic acid increase? During patient hospitalization, the hematic phosphorus had decreased to, 0.8 mg/dl. Diuretic therapy together with acidosis tamponage, and reduced phosphorus feed had been responsible of severe hypo-phosphatemia. Therapy adjustments brought the phosphatemia to normal values and to a substantial improvement of clinical conditions.
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PMID:[Severe hypophosphatemia in intensive care]. 761 39

In an effort to differentiate between alternative mechanistic schemes that have been postulated for Escherichia coli methionine aminopeptidase (eMetAP), the modes of binding of a series of products and phosphorus-based transition-state analogues were determined by X-ray crystallography. Methionine phosphonate, norleucine phosphonate, and methionine phosphinate bind with the N-terminal group interacting with Co2 and with the respective phosphorus oxygens binding between the metals, interacting in a bifurcated manner with Co1 and His178 and hydrogen bonded to His79. In contrast, the reaction product methionine and its analogue trifluoromethionine lose interactions with Co1 and His79. The interactions with the transition-state analogues are, in general, very similar to those seen previously for the complex of the enzyme with a bestatin-based inhibitor. The mode of interaction of His79 is, however, different. In the case of the bestatin-based inhibitor, His79 interacts with atoms in the peptide bond between the P(1)' and P(2)' residues. In the present transition-state analogues, however, the histidine moves 1.2 A toward the metal center and hydrogen bonds with the atom that corresponds to the nitrogen of the scissile peptide bond (i.e., between the P(1) and P(1)' residues). These observations tend to support one of the mechanistic schemes for eMetAP considered before, although with a revision in the role played by His79. The results also suggest parallels between the mechanism of action of methionine aminopeptidase and other "pita-bread" enzymes including aminopeptidase P and creatinase.
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PMID:Insights into the mechanism of Escherichia coli methionine aminopeptidase from the structural analysis of reaction products and phosphorus-based transition-state analogues. 1055 63

The removal of the N-terminal methionine from proteins and peptides is dependent upon a novel class of proteases typified by the dinuclear metalloenzyme methionine aminopeptidase from Escherichia coli (eMetAP). Substantial progress has recently been made in determining the structures of several members of this family. The identification of human MetAP as the target of putative anti-cancer drugs reiterates the importance of this family of enzymes. Determination of the modes of binding to E. coli MetAP of a substrate-like bestatin-based inhibitor, as well as phosphorus-containing transition-state analogs and reaction products has led to a rationalization of the substrate specificity and suggested the presumed catalytic mechanism. The conservation of key active site residues and ligand interactions between the MetAPs and other enzyme of the same fold suggest that avoidance of cross-reactivity may be an important consideration in the design of inhibitors directed toward a single member of the family.
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PMID:Structure and function of the methionine aminopeptidases. 1070 56

Enhanced biological phosphorus removal wastewater treatment plants that use anaerobic digesters for sludge treatment, have high phosphorus concentrations in the sidestreams from their sludge dewatering equipment. To remove phosphorus from such sidestreams controlled struvite crystallisation can be used. Struvite (or MAP) is a naturally occurring crystal of magnesium, ammonium and phosphate. We present operational results obtained with a continuously operated pilot-scale MAP reactor. The pilot-scale reactor (143 l) was an air agitated column reactor with a reaction and a settling zone, based on the Phosnix process of Unitika Ltd., Japan. The influent to the MAP reactor was centrate from the centrifuge that dewaters anaerobically digested sludge at the Oxley Creek wastewater treatment plant in Brisbane. We used a 60% magnesium hydroxide slurry to add the required magnesium to the process and to obtain the alkaline pH value required. The pilot-scale MAP process achieved an ortho-P removal ratio of 94% from an average influent ortho-P concentration of 61 mg/l. The reactor was operated at a pH of around 8.5. Insufficient dosing of magnesium reduced the P removal performance. There was no influence of the hydraulic residence time on the process in the range of 1-8 h. The dry MAP product had cadmium, lead and mercury concentrations well below the legal limits for fertilisers in Queensland, Australia and can be reused as a valuable slow-release fertiliser.
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PMID:Controlled struvite crystallisation for removing phosphorus from anaerobic digester sidestreams. 1125 69

The authors have been engaged in the research and development concerning the recovery of MAP (Magnesium Ammonium Phosphate) using a fluidized-bed crystallized phosphorus removal system. In the reactor of the fluidized-bed crystallized phosphorus removal system, seed crystals (of MAP) are fluidized previously and new MAP crystals are produced on the seed crystal surfaces. Conventionally, the reactor consisted of one reaction tank only, but this practice had the problem that as the crystallization progresses, the seed crystal is grown excessively and as a result, the effective reaction surface areas are decreased and the fluidization effect is degraded, causing the recovery ratio to be decreased. Recently, the authors have devised a two-tank type reactor by adding a sub reaction tank to the reactor (now the main reaction tank) so that the MAP particle size in the main reaction tank may be kept constant making the recovery ratio stable. They conducted a demonstration test with a pilot experimental system of the 2-tank type reactor. For raw water T-P 111 to 507 mg/L, the main reaction tank treated water T-P 14.0 to 79.5 mg/L and phosphorus recovery ratios 84 to 92% were obtained. Because the mean MAP particle size in the main reaction tank could be kept constant, the phosphorus recovery ratio could always be above 80%, realizing stable treatment.
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PMID:Development of a high-efficiency phosphorus recovery method using a fluidized-bed crystallized phosphorus removal system. 1292 33

The effects of diverse phenylaminopyrimidines (PAP), namely PAP-pyridines (type A), PAP-pyrazoles (type B) and PAP-thiazoles (type C), on Neurospora crassa Shear & Dodge has been investigated. The results revealed that type A strongly inhibit the in vitro growth of N crassa, whereas types B and C are much less active. A significant correlation was observed between the Neurospora growth inhibition and the intrinsic activity of type A compounds on the cyclin-dependent protein kinase p34(CDC2) of starfish, suggesting that the target of phenylaminopyrimidines in fungi is a cyclin-dependent protein kinase (CDK). The phenylaminopyrimidine-binding CDKs Phoss (major band) and CDC2 (minor band) involved in phosphorus uptake, glycogen synthesis and the cell cycle were identified from N crassa by affinity chromatography on phenylaminopyrimidine-sepharose. Comparative experiments with different protein kinases revealed the importance of the side chain of phenylaminopyrimidines for their target selectivity. A type B compound was found to selectively inhibit the MAP-kinase OS-2 involved in the osmoregulatory pathway of Neurospora.
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PMID:Evaluation of phenylaminopyrimidines as antifungal protein kinase inhibitors. 1595 47

In this paper, phosphorus balances are calculated for the wastewater purification and sludge treatment stages for wastewater treatment plants (WWTPs) applying Enhanced Biological Phosphorus Removal (EBPR). The possible P-recovery potential is then estimated and evaluated regarding different locations along the process of wastewater purification and sludge treatment, taking the different phosphorus bonding forms into account. Caused by the more favourable bonding forms in the excess sludge as well as possibly also in the sludge ash a recovery of the phosphorus seems especially favoured for WWTPs with EBPR. The processes available for a P recycling are named, and special regard is given to the Phostrip-process, which is a possible recycling process already tested in practice. Further R&D demand consists in basic research regarding disintegration, fermentation or acidic total digestion of excess sludge followed by phosphorus precipitation including separation of the precipitates, MAP-precipitation and separation from digested sludge and on the ability to extract phosphorus and heavy metals from sewage sludge ash. These investigations are a precondition to enable purposeful process developments. At the present state the cost of recycled phosphorus earned from wastewater, sludge and ash, respectively, are a multiple higher than the costs for raw phosphate taking into account the suitable processes. Thus, up to now no phosphorus recycling with a defrayal of costs is possible. The future importance of phosphorus recycling will depend on the market price for raw phosphate, the recycling costs and, furthermore, on the general political framework.
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PMID:Phosphorus recycling in sewage treatment plants with biological phosphorus removal. 1645 32

A novel granular medium consisting (1.5-5 mm in diameter) of inert perlite particles as nuclei and an effective surface layer containing sulfur, CaCO3 and Mg(OH)2 was developed for advanced treatment of agro-industrial wastewater. The performance of the medium was examined with a laboratory-scale down-flow fixed-bed column reactor using piggery wastewater, which had been treated by an upflow anaerobic sludge blanket reactor and a trickling filter. The removal efficiency of NOx- -N was more than 70% with a NOx- -N loading rate of less than approximately 0.3 kg Nm(-3) d(-1); the removal efficiency dropped due to the accumulation of nitrite when the loading rate exceeded that value. A significant drop of phosphate and Mg2+ concentrations occurred when the effluent pH exceeded 7.9. Ammonium was removed with an average removal efficiency of 12.4%. These results indicated that the crystalline reaction of PO4(3-), Mg2+ and NH4+ (MAP reaction) under alkaline conditions contributed to the removal of phosphate. This medium could be useful for the simultaneous reduction of nitrogenous and phosphorus compounds in biologically treated agro-industrial wastewater.
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PMID:Autotrophic denitrification and chemical phosphate removal of agro-industrial wastewater by filtration with granular medium. 1670 61

To realize the simultaneous removal and recovery of phosphate and partial nitrogen from stale human urine, a series of lab-scale jar tests, adopting MgCl2 x 6H2O as precipitant, were conducted to study the influence of the molar ratio of Mg/PO4(3-)-P, pH, mixing speed, reaction time and precipitation time on MAP precipitation. The experiment results showed that the molar ratio of Mg/PO4(3-)-P was found to be a very important operating parameter to affect phosphorus recovery efficiency. When the molar ratio of Mg/PO4(3-)-P was above 1.3:1, the phosphorus recovery efficiency was above 95% and the residual phosphorous was less than 10 mg/L in the solution. Increasing pH with 10 mol/L NaOH solution could not increase the recovery phosphorus efficiency obviously. Without pH control, the optimal parameters of reaction time, precipitation time and mixing speed could be set at 20 min, 2.0 h and 120 r/min, respectively. To reveal the chemical characteristics of MAP products from human urine, three MAP product samples, with no pH adjustment and under the above optimal operation condition, were obtained at different Mg/PO4(3-)-P molar ratios of 1:1, 1.3:1 and 1.5:1, respectively, and analyzed with SEM, XRD and ICP instrumentation. These precipitates were identified as nearly pure struvite (12.62% of P, 5.71% of N and 9.91% of Mg) with the presence of trace calcium, potassium and sodium. The contents of phosphorus, nitrogen and magnesium in the precipitates were 13.54%, 5.34% and 9.01% (Mg/PO4(3-)-P = 1:1), 13.78%, 5.23% and 9.36% (Mg/PO4(3-)-P = 1.3:1), as well as 13.34%, 5.12% and 9.15% (Mg/PO4(3-)-P = 1.5:1), respectively.
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PMID:[Phosphorus removal and recovery from human urine with MAP crystallization]. 1826 83

Removal and recovery of phosphorus from sewage in form of MAP (magnesium ammonium phosphate) have attracted attention from the viewpoint of eutrophication prevention and phosphorus resource recovery as well as scaling prevention inside digestion tanks. In this work, phosphorus recovery demonstration tests were conducted in a 50 m3/d facility having a complete mixing type reactor and a liquid cyclone. Digested sludge, having 690 mg/L T-P and 268 mg/L PO4-P, was used as test material. The T-P and PO4-P of treated sludge were 464 mg/L and 20 mg/L achieving a T-P recovery efficiency of 33% and a PO4-P crystallization ratio of 93%. The reacted phosphorus did not become fine crystals and the recovered MAP particles were found to be valuable as a fertilizer. A case study in applying this phosphorus recovery process for treatment of sludge from an anaerobic-aerobic process of a 21,000 m3/d sewage system, showed that 30% of phosphorus concentration can be reduced in the final effluent, recovering 315 kg/d as MAP.
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PMID:Development of a process for the recovery of phosphorus resource from digested sludge by crystallization technology. 1830 26


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