Effect of inorganic phosphate

Bryant RD, Laishley EJ. 1993. The effect of inorganic phosphate and hydrogenase on the corrosion of nuld steel. Appl Microbiol Biotechnol 38 824-7. 

Ueki, K. Sato, S. (1971). Effect of inorganic phosphate on the extracellular acid phosphatase activity of tobacco cells cultured in vitro. Physiologia Plantarum 24, 506-11. 

Tesi, C., Colomo, F., Nencini, S., Piroddi, N., and Poggesi, C. (2000). The effect of inorganic phosphate on force generation in single myofibrils from rabbit skeletal muscle. Biophys.J. 78, 3081-3092. 

The results discussed in this article showed that the effect of inorganic phosphate on the course of the Maillard reaction may be described by general base catalysis following approximately first-order kinetics. The effect is optimum in the pH-range between 5 and... 

Osterman A, Arner A (1995) Effects of inorganic phosphate on cross-bridge kinetics at different activation levels in skinned guinea-pig smooth muscle. J Physiol (Lond) 484 369-383... 

UchidaM,SawadaH,AsaiT, Suzuki M (1981) Effect of inorganic phosphate and dissolved oxygen on production of maridomycin. J Ferment Technol 59 399-401... 

The inhibitory effect of inorganic phosphate on biosynthetic pathways of secondary metabolites including non--phosphorylated intermediates is explained less readily. The action usually involves the derepression of synthesis of enzymes which carry out the formation of secondary products after the inorganic phosphate has been exhausted (4). The study by Martin et al. (23) of the effect of orthophosphate on candicidin biosynthesis in Streptomyces griseus suggested that inorganic phosphate either inhibits the activity of candicidin synthases or represses their synthesis (24). Inorganic phosphate also represses the synthesis of anhydrotetracycline hydratase in Streptomyces aureofaciens while benzyl thiocyanate abolishes its inhibitory effect (4). 

Increased level of inorganic phosphate leads to a rise in total adenylate level (28) which favours the oxidative phosphorylation and promotes phosphorylation and further carbohydrate metabolism, As in the case Of glucose and other rapidly metabolized substrates, this results in an accumulation of inhibitory catabolites. The mechanism of inhibitory effect of inorganic phosphate may be identical with that of catabolite repression. The action of some positive effectors of secondary metabolite synthesis which also abolish the inhibitory effect of inor-... 

Numerous effects of inorganic phosphates when added to milk have been reported. Many of these are explained in terms of precipitation of calcium phosphate and calcium caseinate, or the removal of these compounds by formation of soluble complexes. 

The modes of action for niclosamide are interference with respiration and blockade of glucose uptake. It uncouples oxidative phosphorylation in both mammalian and taenioid mitochondria (22,23), inhibiting the anaerobic incorporation of inorganic phosphate into adenosine triphosphate (ATP). Tapeworms are very sensitive to niclosamide because they depend on the anaerobic metaboHsm of carbohydrates as their major source of energy. Niclosamide has selective toxicity for the parasites as compared with the host because Httle niclosamide is absorbed from the gastrointestinal tract. Adverse effects are uncommon, except for occasional gastrointestinal upset. 

Figure 4.9 Effect of reduced glutathione (GSH) (0.25-1.0 ihm) and oxidized glutathione (GSSG) (0.25-1.0 mM) on ouabain-sensitive Na/K ATPase activity. An isolated Na/K ATPase preparation was prepared from fresh bovine ventricular tissue. Na/K ATPase activity was determined and quantified by the ouabain-sensitive hydrolysis of ATP to yield Inorganic phosphate. The rate of inorganic phosphate production was compared prior to and following the addition of either GSH or GSSG to the Incubation mixture. The data are presented as...

Covalent modification of enzymes (molecular weight of several hundreds or thousands) by the incorporation of inorganic phosphate in the form of P03 (formula weight = 85), seems to represent a small chemical change in the enzyme yet is an important control mechanism of enzyme activity. Explain how phosphorylation can exert its controlling effect on the activity of the enzyme. 

There seems to be a specific requirement for Mg2+, as it is much more effective than other divalent cations, the sequence being Mg2+ Zn2+> Co2+, Mn2+ Cd2+. This is due to the slower rate of release of inorganic phosphate from the enzyme in the presence of cations other than Mg2+, and reflects the high lability of Mg2+-oxygen bonds.291... 

In 1978 Cohn and Hu (1) demonstrated the isotopic effect by 180 on the Ip-nmr spectrum of inorganic phosphate. For each that replaces an 1 0, an upfield shift of 0.021 ppm results. Thus the chemical shift for HP O 58 is 0.084 ppm downfield from Hpl 04=. Based on this observation it is obvious that any chemical event that potentially involves substitution or exchange of an 0 for 16() in phosphorus containing compounds can be followed by monitoring the Ip-nmr spectrum throughout the course of the reaction. This article describes experiments from my laboratory on two enzymes that catalyze phosphoryl transfer reactions and our use of the [1 0/1 0] lp-nmr methodology to detect intermediates in the enzymic reactions. 

The problems associated with the separation of phosphate esters are the tendency of the spots to diffuse difficulty of reproducing RF values variability of RF values with complexity of the mixture being resolved and distance of solvent travel proper purification and equilibration of the filter paper effect of inorganic ions in natural mixtures and the choice of suitable solvent mixtures for desired separations. The problem of detecting the separated spots is somewhat simpler. In addition to methods applicable to the detection of reducing sugars (e.g., use of aniline salts fructose esters are detected by naphthoresorcinol-acid), methods depending on phosphomolybdate formation are most commonly used. Hanes and Isher-... 

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