Acid phosphatase effects

In soil, the chances that any enzyme will retain its activity are very slim indeed, because inactivation can occur by denaturation, microbial degradation, and sorption (61,62), although it is possible that sorption may protect an enzyme from microbial degradation or chemical hydrolysis and retain its activity. The nature of most enzymes, particularly size and charge characteristics, is such that they would have very low mobility in soils, so that if a secreted enzyme is to have any effect, it must operate close to the point of secretion and its substrate must be able to diffuse to the enzyme. Secretory acid phosphatase was found to be produced in response to P-deficiency stress by epidermal cells of the main tap roots of white lupin and in the cell walls and intercellular spaces of lateral roots (63). Such apoplastic phosphatase is safe from soil but can be effective only when presented with soluble organophosphates, which are often present in the soil. solution (64). However, because the phosphatase activity in the rhizo-sphere originates from a number of sources (65), mostly microbial, and is much higher in the rhizosphere than in bulk soil (66), it seems curious that plants would have a need to secrete phosphatase at all. 

Associated with NA depletion from host nuclei was the diminution and deformation of these nuclei, significant depletion of host nucleoskeletal protein lamin b, and significant reductions in levels of host cell RNA, protein and acid phosphatase activity. In contrast, host infiltrating cells showed no such changes, supporting an infected cell-specific effect. These observations support the possibility that NA are synthesized by the parasite and modulate host nuclear functions. However, release of other parasite secretory products, not analysed, might have been inhibited in these experiments also. 

The effects of organic molecules and phosphate on the adsorption of acid phosphatase on various minerals, and kaolinite in particular, have been investigated by Huang et al. [97]. The Langmuir affinity constant for AcP adsorption by kaolinite follows the series tartrate (K — 97.8) > phosphate (K= 48.6) > oxalate (K — 35.6) > acetate (K= 13.4). At low concentration, acetate even promoted the adsorption of acid phosphatase. It was considered that competitive interactions between anionic adsorbates can occur directly through competition for surface sites and indirectly through effects of anion adsorption on the surface charge and protonation. 

Nuruzzaman H, Lambers H, Bolland MDA, Veneklaas EJ (2006) Distribution of carboxylates and acid phosphatase and depletion of different phosphorus fractions in the rhizosphere of a cereal and three grain legumes. Plant Soil 281 109-120 Olde Venterink H, Wassen MJ, Belgers JDM, Verhoeven JTA (2001) Control of environmental variables on species density in fens and meadows importance of direct effects and effects through community biomass. J Ecol 89 1033-1040. doi http //www.blackwell-synergy.com/ doi/abs/10.111 l/j.1365-2745.2001.00616.x... 

AGIRE computer program for, 249, 79-81, 225-226 comparison to analysis based on rates, 249, 61-63 complex reactions, 249, 75-78 experimental design, 249, 84-85 inhibitor effects, 249, 71-75 potato acid phosphatase product inhibition, 249, 73-74 preliminary fitting, 249, 82-84 prephenate dehydratase product inhibition, 249, 72-73 product inhibition effects, 249, 72-73 prostate acid phosphatase phenyl phosphate hydrolysis, 249, 70 reactions with two substrates, 249, 75-77 reversible reactions, 249, 77-78 with simple Michaelian enzyme, 249, 63-71 [fitting equations, 249, 63] with slow-binding inhibitors, 249, 88 with unstable enzymes, for kinetic characterization, 249, 85-89. 

DEGREE OF DISSOCIATION HENDERSON-HASSELBALCH EQUATION ACID-BASE EQUILIBRIUM CONSTANTS BR0NSTED THEORY LEWIS ACID ACIDITY FUNCTION LEVELING EFFECT ACIDITY FUNCTION ACID-LABILE SULFIDES ACID PHOSPHATASE ACONITASE... 

Enzymes activities are particularly sensitive to the anticoagulant used in collecting the specimen. Heparin inhibits acid phosphatase (W16) and muramidase (Z5). Amylase activity is inhibited by oxalate or citrate (MIO), and lactic dehydrogenase and acid phosphatase lose activity in oxalate (C2). Alkaline phosphatase is stable in oxalate, oxalate-fluoride, or heparin, but 25 mAf citrate inhibits 50% of the activity, and as little as 50 mlf EDTA is completely inhibitory (B19). Leucine aminopeptidase is inhibited by EDTA, as is creatine phosphokinase (F3). Amylase activity has been reported to be only 83% of that in serum when oxalate or citrate-plasma is used (MIO). Heparin plasma appears to have no inhibitory effect. Despite the fact that clotting factor V is not stable in oxalate or EDTA, these are often used as anticoagulants to obtain plasma for prothrombin determinations (Z2, Z4). 

Chronic in vivo hemolysis produces serum lactic dehydrogenase elevations in patients with mitral or atrial valve cardiac prosthesis (J2). In a series of 11 such patients these increases ranged from 1.1 to 1.6 times the upper limit of normal (S29). Blood pH is altered in hemolyzcd specimens because carbonic anhydrase is liberated from the erythrocytes and presumably alters the distribution of H2CO3 and NaHCOs (B2). Hemolysis will effect acid phosphatase activity if the substrate is hydrolyzed by erythrocyte acid phosphatase. Thus, hemolysis would be of concern if phenyl phosphate was the substrate, but would have a negligible effect if )8-glycerophosphate, which is not hydrolyzed by red cell acid phosphatase, was used (Bl). 

There are stability problems in urines stored for analysis. Fifty percent of delta-aminolevulinic acid was lost in specimens stored without preservative and exposed to light for 24 hours (V3). The loss increased to 80% in 48 hours, 85% in 72 hours, and 95% in 2 weeks. However, the same specimens acidified with tartaric acid and stored in the dark lost 2% of the aminolevulinic acid in 72 hours and 6% in 2 weeks (V3). The destruction of catecholamines collected in nonacidified urine specimens is well documented (Cll). Urinary acid phosphatase was destroyed on freezing (S15). The effect was related to increasing salt concentration during freezing and was prevented by the addition of albumin (S15). 

Rl. Roubrick, M., and Winsten, S., Effect of routine rectal examination on the level of serum acid phosphatase. J. Urol. 88, 288-291 (1962). 

Schwartz, M. K., Daniel, O., Ying, S. H., and Bodansky, O., Effect of storage in deep freeze upon activity of urinary acid phosphatase. Amer. J. Clin. Pathol. 26, 513-516 (1956). 

No gross or microscopic lesions were observed in the kidneys of rats treated dermally with 100 mg nickel/kg/day as nickel sulfate for 15 or 30 days (Mathur et al. 1977). In this study, there was no indication that the rats were prevented from licking the nickel from the skin therefore, the animals could have been orally exposed. Increased Mg ATPase was observed in the kidneys of guinea pigs treated with 100 mg nickel/kg/day as nickel sulfate placed on skin of the back for 30 days (Mathur and Gupta 1994). No effect was noted at 15 days, and dermal nickel exposure had no effect on kidney acid phosphatase or glucose-6-phosphatase activities. 

Testicular effects were also investigated after oral administration of 2000 mg/kg bw di(2-ethylhexyl) phthalate for seven consecutive days to 13-week-old male Wistar rats (Saxena et al., 1985). Degeneration was observed in about 40% of the seminiferous tubules. Loss of succinic dehydrogenase, NADH-diaphorase and acid phosphatase activity and increases in adenosine triphosphatase, glucose-6-phosphate dehydrogenase and alkaline phosphatase activity were observed in treated rats. 

Acid phosphomonoesterase (EC 3.1.3.2). Milk contains an acid phosphatase which has a pH optimum at 4.0 and is very heat stable (LTLT pasteurization causes only 10-20% inactivation and 30 min at 88°C is required for full inactivation). Denaturation of acid phosphatase under UHT conditions follows first-order kinetics. When heated in milk at pH 6.7, the enzyme retains significant activity following HTST pasteurization but does not survive in-bottle sterilization or UHT treatment. The enzyme is not activated by Mg2+ (as is alkaline phosphatase), but it is slightly activated by Mn2+ and is very effectively inhibited by fluoride. The level of acid phosphatase activity in milk is only about 2% that of alkaline phosphatase activity reaches a sharp maximum 5-6 days post-partum, then decreases and remains at a low level to the end of lactation. 

Although casein is a substrate for milk acid phosphatase, the major caseins, in the order as(asl + as2) > (3 > k, also act as competitive inhibitors of the enzyme when assayed on p-nitrophenylphosphate, probably due to binding of the enzyme to the casein phosphate groups (the effectiveness of the caseins as inhibitors is related to their phosphate content). 

The changes in calvarial phosphatase activities observed in animals treated with 25-(OH)D3 are totally different from those obtained with either 1.25-(OH)2D3 or 24.25—(OH)2D3. This fact indicates that physiological doses of 25-(OH)D3 may have an effect on cellular activity, independent of the conversion of this metabolite into these dihydroxyderivatives. The various effects of these vitamin D3 metabolites cannot be correlated with changes in serum calcium and/or phosphate concentrations. Among those factors other than serum calcium and phosphate concentrations that may be involved in the mechanism of action of vitamin D3 metabolites on bone phosphatase activities, the parathyroid hormone is of importance. This hormone is known to be a potent activator of bone phosphatases223,224,228. Parathormone increases the content of alkaline, neutral and acid phosphatases in mouse calvaria in vitro. Calcitonin does not prevent the increase of those enzymes while dichloromethylene diphosphonate causes a decrease in acid phosphatase and pyrophosphatase226. ... 

One enzyme present in the surfactant fluid is an acid phosphatase able to hydrolyze phosphatidylglycerol phosphate, perhaps functioning in the final step of biosynthesis of the phosphatidylglycerol present in the surfactant.6 Study of the action of the natural lung surfactant has led to development of artificial surfactant mixtures that are being used effectively to save many lives.d... 

Effect of Substrate and Buffer on Kinetic Constants of Acid Phosphatase ... 

Reiner and his colleagues (40) demonstrated that fluoride inhibition of prostatic acid phosphatase showed interesting and unexpectedly complex kinetics. The unusual nature of the inhibition can readily be appreciated from Fig. 4 (40). As the fluoride concentration is increased over a 1000-fold range, the extent of inhibition rises and then subsequently falls with a further increase of inhibitor. At lower fluoride concentration, the inhibition is clearly competitive. Two possibilities were explored for an explanation of these unusual concentration effects of inhibition. There could be two forms of fluoride in the reaction mixtures the inhibitory form and the second which predominates at higher... 

Prostatic acid phosphatase is irreversibly inhibited by reaction with iodine monochloride at pH 8.1. Figures 9 and 10 (60) show the effect of concentration of IC1 and the time course of the reaction. Very rapid inactivation occurred at concentrations of 0.05 vaM IC1. Further increase in the concentration of the reagent produced further inactivation but... 

Table XI (73) shows the Stokes radii and frictional ratio obtained by the study of purified acid phosphatase. The preparations show molecular homogeneity during filtration on Sephadex G-100, in the analytical ultracentrifuge, and during immunolectrophoresis. These data obtained by chromatography on Sephadex G-200 indicate that human prostatic acid phosphatase has an effective Stokes radius of 47.1 A and a frictional ratio of 1.56, suggesting considerable molecular asymmetry.

Effect of Metallic Ions on the Acid Phosphatases of Plasma, Prostate, and Red Cells0 1... 

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