Phosphatases Phosphate

Prostatic acid phosphatase Phosphate ( P04 ), vanadate ( ), arsenate ( AsO ), molybdate ( MoO ), L-(+(-tartrate, benzylaminophosphonic acid and benzylaminobenzylphosphonic acid, W-propyltartramate Aliphatic alcohols... 

Figure 8. Absorption spectra of cohalt phosphatase phosphate...

Purple acid phosphatase Phosphate ester hydrolysis 182)... 

Deming and Pardue studied the kinetics for the hydrolysis of p-nitrophenyl phosphate by the enzyme alkaline phosphatase. The progress of the reaction was monitored by measuring the absorbance due to p-nitrophenol, which is one of the products of the reaction. A plot of the rate of the reaction (with units of pmol mL s ) versus the volume, V, (in milliliters) of a serum calibration standard containing the enzyme yielded a straight line with the following equation... 

Phosphatase Phosphatase enzymes Phosphatase tests Phosphatation Phosphate... 

A rather more specific mechanism of microbial immobilization of metal ions is represented by the accumulation of uranium as an extracellular precipitate of hydrogen uranyl phosphate by a Citrobacter species (83). Staggering amounts of uranium can be precipitated more than 900% of the bacterial dry weight Recent work has shown that even elements that do not readily form insoluble phosphates, such as nickel and neptunium, may be incorporated into the uranyl phosphate crystallites (84). The precipitation is driven by the production of phosphate ions at the cell surface by an external phosphatase. 

Chemiluminescence and bioluminescence are also used in immunoassays to detect conventional enzyme labels (eg, alkaline phosphatase, P-galactosidase, glucose oxidase, glucose 6-phosphate dehydrogenase, horseradish peroxidase, microperoxidase, xanthine oxidase). The enhanced chemiluminescence assay for horseradish peroxidase (luminol-peroxide-4-iodophenol detection reagent) and various chemiluminescence adamantyl 1,2-dioxetane aryl phosphate substrates, eg, (11) and (15) for alkaline phosphatase labels are in routine use in immunoassay analyzers and in Western blotting kits (261—266). 

Phosphatase Test. The phosphatase [9001-78-9] test is a chemical method for measuring the efficiency of pasteurization. AH raw milk contains phosphatase and the thermal resistance of this enzyme is greater than that of pathogens over the range of time and temperature of heat treatments recognized for proper pasteurization. Phosphatase tests are based on the principle that alkaline phosphatase is able, under proper conditions of temperature and pH, to Hberate phenol [108-95-2] from a disodium phenyl phosphate substrate. The amount of Hberated phenol, which is proportional to the amount of enzyme present, is determined by the reaction of Hberated phenol with 2,6-dichloroquinone chloroimide and colorimetric measurement of the indophenol blue formed. Under-pasteurization as well as contamination of a properly pasteurized product with raw milk can be detected by this test. 

Rapid inactivation of added lincomycin was found to result from the growth of Streptomjces rochei in a synthetic medium the antibiotic was converted into lincomycin 3-phosphate [23670-99-7] (5, R = CH3, R = PO3H2, R = SCH3), C2gH33N202PS, readily cleaved back to the antibiotic upon treating with alkaline phosphatase (53). 

An enzyme-amplified detection scheme, based on tire coupling of a streptavidin-alkaline phosphatase conjugate and biotinylated target sequences was then applied. The enzyme catalysed the hydrolysis of the elecn oiiractive a-naphthyl phosphate to a-naphtlrol this product is elecU oactive and has been detected by means of differential... 

FIGURE 23.8 Glu cose-6-phosphatase is localized in the endoplasmic reticulum membrane. Conversion of glucose-6-phosphate to glucose occurs during transport into the ER. 

Hydrolysis 10 mmol of the phosphate salt are dissolved by swirling with Dowex AG50W-X8 (H ) in 200 mL of water. After filtration, the pH is adjusted to 6.0, acid phosphatase (150 U EC 3.1.3.2) is added and the mixture is incubated at 25 CC until complete conversion, as monitored by TLC (48 h). The solution is desalted by ion exchange, concentrated in vacuo, and the residue is crystallized from ethanol to give colorless crystals of D-sorbosc yield 1.6g (89%). 

The nonphosphorylated compounds may be readily obtained by chemical or, preferentially, by mild phosphatase hydrolysis of the 1-phosphates. Reactor design17 and enzyme immobilization techniques18 have been evaluated for efficient practical syntheses. Owing to the narrow specificity... 

Lipid phosphate phosphohydrolases (LPPs), formerly called type 2 phosphatidate phosphohydrolases (PAP-2), catalyse the dephosphorylation of bioactive phospholipids (phosphatidic acid, ceramide-1-phosphate) and lysophospholipids (lysophosphatidic acid, sphingosine-1-phosphate). The substrate selectivity of individual LPPs is broad in contrast to the related sphingosine-1-phosphate phosphatase. LPPs are characterized by a lack of requirement for Mg2+ and insensitivity to N-ethylmaleimide. Three subtypes (LPP-1, LPP-2, LPP-3) have been identified in mammals. These enzymes have six putative transmembrane domains and three highly conserved domains that are characteristic of a phosphatase superfamily. Whether LPPs cleave extracellular mediators or rather have an influence on intracellular lipid phosphate concentrations is still a matter of debate. 

SIP is formed from sphingosine by sphingosine kinases (SphKs). Degradation of SIP occurs either reversibly by lipid phosphate phosphohydrolases (LPPs) and SIP phosphatases (SPPs), or irreversibly by SIP lyase (SPL) (Fig. 1). The localization of SIP production is highly important since SIP plays a role both as extracellular mediator and as intracellular... 

A phosphatase is an enzyme that hydrolyzes phospho-monoesterases, a reaction yielding free phosphate and alcohol. Substrates for phosphatases include both... 

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