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Rapid rise of serum acid phosphatase after irradiation of metastatic carcinoma of prostate.

An eighty-two-year-old man with metastatic prostatic adenocarcinoma was treated with radiation therapy to the lumbar region of the spinal column. A rapid rise in his acid phosphatase activities developed, increasing thirty-eight-fold in two days. He died on the second day post-therapy of hemorrhagic complications. The rapid increase in acid phosphatase activity was due to release from injured or dying prostatic adenocarcinoma cells.

Acid Phosphatase↗

Acid phosphatase of the yeast Rhodotorula rubra. Purification and properties of the enzyme.

1. Acid phosphatase from the yeast Rhodotorula rubra was purified 44-fold. The purification procedure involved mechanical disruption of cells, precipitation with ethanol, chromatography on DEAE- and CM-cellulose. 2. The purified enzyme is homogeneous in polyacrylamide gels at pH 4.5, 9.5 and 8.4. Carbohydrate content accounts for 57% of the total weight. The optimum pH is at 4.0-4.6, and the enzyme is stable over pH range from 2.6 to 6.0. Full activity was retained on 60-min incubation at 50 degrees C, but it was reduced by half on 60-min incubation at 65 degrees C. 3. Specificity of the enzyme is fairly broad; monoesters of carbohydrates, and nucleosides and inorganic pyrophosphate can serve as substrates. Km was found to be 1 X 10(-4) M for p-nitrophenyl phosphate as a substrate. The enzyme is inhibited by molybdate, phosphate, arsenate and fluoride ions.

Acid Phosphatase↗

Chromatographic separation of two acid phosphatases from rat bone.

Extracts of tibiae of suckling rats were prepared with 0.3 M KCl containing 0.1% Triton X-100 and were chromatographed with CM-52 cellulose. Most of the acid phosphatase activity determined with p-nitrophenylphosphate (p-NPP) was bound to the cellulose and could be eluted with a sodium acetate buffer gradient in 2 distinct peaks. The major peak, E2, was bound strongly to the cellulose and showed high activity with p-NPP and inorganic pyrophosphate (P-Pi), but only slight activity with beta-glycerophosphate (beta-GP) and was unaffected by tartrate. The minor peak, E1, was weakly bound to the adsorbent, showed equal activity with p-NPP and beta-GP, but negligible activity with P-Pi and was completely inhibited by tartrate. These results support earlier evidence suggesting that bone contains at least 2 different acid phosphatases and that the more abundant enzyme may function as a pyrophosphatase.

4-Nitrophenylphosphatase↗

Acid phosphatase and peroxidase in "resting" acinar cells of the major salivary glands of cats and their possible movement into secretory granules.

After fixation of perarterial perfusion using an aldehyde mixture, salivary tissues were prepared for ultrastructural cytochemistry of acid phosphatase or peroxidase. Great variations in the distributions of the reaction product occurred, often within the same cell. Acid phosphatase staining occurred not only in lysosomes and sometimes in a GERL system, but a diffuse cytoplasmic component was also found in submandibular central acinar cells and to a lesser extent in parotid acini and variable staining occurred in the secretory granules of these cells. Peroxidase was variably associated with rough endoplasmic reticulum in submandibular demilunar cells, parotid acini, and more strongly in some sublingual cells. The secretory granules of the latter were darkly stained, but in parotid granules there was variable staining and least staining occurred in the granules of submandibular demilunes. These results are thought to indicate that not all enzymes present in secretory granules have reached there by an elective secretory process. Sometimes they appear to have entered the granules haphazardly, possibly having been enzymes associated with intracellular cisternal channels for transport or metabolism of other secretory substances and ultimately to have passed into the cisternal channels by chance or as part of a natural removal of redundant material.

Acid Phosphatase↗

Evidence for phosphorylation of the extracellular acid phosphatase of Leishmania donovani.

The presence of two phosphorylated molecular species in the culture supernatants of axenically cultivated Leishmania donovani promastigotes was demonstrated by biosynthetically labeling cultures with [32P]phosphate. One of these species was resolved into two bands with Mr's of 149,000 and 97,000 by dissociating polyacrylamide gel electrophoresis and copurified with the extracellular acid phosphatase activity produced by the promastigotes. The site of phosphorylation of the extracellular acid phosphatase is not yet known.

Acid Phosphatase↗

1H NMR and NOE studies of the purple acid phosphatases from porcine uterus and bovine spleen.

The diiron active sites of the purple acid phosphatases from porcine uterus (also called uteroferrin, Uf) and bovine spleen (BSPAP) and their complexes with tungstate are compared by 1H NMR and NOE techniques. The paramagnetically shifted features of the 1H NMR spectrum of reduced BSPAP are similar to those of reduced Uf, while the spectra of the tungstate complexes are almost identical. These observations suggest that the two active sites are quite similar, in agreement with the greater than 90% sequence homology found in the two enzymes. Nuclear Overhauser effect (NOE) experiments on the His N-H resonances show that the Fe(III)-His residue is N epsilon-coordinated, while the Fe(II)-His is H delta-coordinated in both enzymes. On the basis of the above NMR and NOE results, our previously proposed model for the dinuclear iron active site of Uf [Scarrow, R. C., Pyrz, J. W., & Que, L., Jr. (1990) J. Am. Chem. Soc. 112, 657-665] is corroborated, refined, and found to represent the diiron center of BSPAP as well.

Acid Phosphatase↗

Structure of the human lysosomal acid phosphatase gene.

We have isolated a 12-kb genomic clone, which encodes human lysosomal acid phosphatase (LAP), a lysosomal membrane glycoprotein. The human LAP gene has a size of about 9 kb and contains 11 exons (83-947 bp in size). The signal sequence and the first eight amino acids of the LAP protein are encoded by exon 1, the remaining luminal domain by exons 2-10 and the transmembrane and cytoplasmic domains, as well as the 3'-untranslated region, by exon 11. The sequence of the LAP gene confirmed the sequence deduced from the cDNA clone except for nucleotide 1917 in the 3'-untranslated region, where T is changed to C. The 5'-flanking sequence shows promoter activity, as analysed by coupling to bacterial chloramphenicol acetyltransferase. S1-nuclease-protection and primer-extension analysis demonstrate transcription initiation at multiple sites clustering within 23 bp upstream of the translation-initiation codon. Sequences characteristic for promoter regions like TATA-box and CAAT-box sequences could not be identified at typical positions. The absence of these sequences, the high GC content (63.5%), two GC boxes and a region complying with the properties of a CpG island, indicate that LAP is a housekeeping gene.

Acid Phosphatase↗

Cytochemical studies on T and B lymphocytes and lymphoblasts with special reference to acid phosphatase.

Lymphoblasts from ten patients with ALL or stage IV malignant lymphoma were studied cytochemically and investigated for rosette-forming capacity with sheep red blood cells (SRBC) as a T cell surface marker. SRBC binding capacity and acid phosphatase or beta-glucuronidase were tested simultaneously in single lymphocytes isolated from normal blood donors. Our results suggest that the presence of acid phosphatase (and beta-glucuronidase) represents a functional state of lymphocytes or lymphoblasts qualitatively independent of T cell differentiation, but quantitatively more pronounced in T cells than in B lymphocytes or non-T lymphoblasts.

Acid Phosphatase↗

Rapid screening method for osteoclast differentiation in vitro that measures tartrate-resistant acid phosphatase 5b activity secreted into the culture medium.

BACKGROUND: Osteoclasts secrete tartrate-resistant acid phosphatase (TRAP; EC 3.1.3.2) 5b into the circulation. We studied the release of TRAP 5b from osteoclasts using a mouse in vitro osteoclast differentiation assay. METHODS: We developed and characterized a polyclonal antiserum in rabbits, using purified human osteoclastic TRAP 5b as antigen. The antiserum was specific for TRAP in Western analysis of mouse osteoclast culture medium and was used to develop an immunoassay. We cultured mouse bone marrow-derived osteoclast precursor cells for 3-7 days with or without clodronate in the presence of vitamin D and analyzed the number of osteoclasts formed and the amount of TRAP 5b activity released into the culture medium. RESULTS: TRAP 5b activity was not secreted from osteoclast precursor cells. Addition of clodronate-containing liposomes decreased in a dose-dependent manner the number of osteoclasts and TRAP 5b activity released in 6-day cultures. The amount of TRAP 5b activity in the medium detected by the immunoassay correlated significantly with the number of osteoclasts formed (r = 0.94; P<0.0001; n = 120). CONCLUSIONS: The TRAP 5b immunoassay can be used to replace the laborious and time-consuming microscopic counting of osteoclasts in the osteoclast differentiation assay and to test the effects of potential therapeutic agents on osteoclast differentiation, enabling fast screening of large amounts of potential therapeutic agents.

Acid Phosphatase↗

Amino acid phosphatase activity of alkaline phosphatase. A possible role of protein phosphatase.

Alkaline phosphatase (ALP) hydrolyzed phosvitin and amino acid phosphates demonstrating nonisotropy at different pH. Orthovanadate, a protein phosphatase inhibitor, more specifically inhibited the serine and tyrosine phosphatase activities of ALP than that of threonine phosphatase at concentrations > 0.1 mM or 0.01 mM, respectively. Calyculin A and okadaic acid at increased concentrations increased ALP amino acid phosphatase activity. Bisphosphonates, such as disodium-1-hydroxy-1-aminopropylidine-1,1-diphosphonate (APD) and ethane-1-hydroxy-1,1-diphosphonate (HEBP), at increased concentrations, inhibited ALP amino acid phosphatase activity. These results suggest that ALP may function as a protein phosphatase. In terms of protein kinase inhibitors, N-[2-(methylamino)ethyl]-5-isoquinolinesulfonamide, N-(6-aminoheyxl)-5-chloro-1-naphthalenesulfomide hydrochloride and 4',5,7-trihydroxyisoflavone had little effect on ALP amino acid phosphatase activity. Staurosporine slightly enhanced ALP serine and threonine phosphatase activities at a concentration of 0.1 mM. These results suggest that protein phosphatase activity does not depend on the protein kinase activity of ALP, since duality between the former and the latter is not supported. ALP may function less as a protein kinase than as a protein phosphatase. The coupling mechanism of phosphate dynamics may be regulated indirectly.

Alkaline Phosphatase↗

Stable expression of human tartrate-resistant acid phosphatase isoforms by CHO cells.

OBJECTIVE: In human serum, type-5 tartrate-resistant acid phosphatase (TRACP) exists as two closely related isoforms: 5a and 5b. Serum isoform 5b is an osteoclast product that reflects bone resorption rate and is frequently increased in diseases of increased bone turnover. Isoform 5a protein is often increased in rheumatoid arthritis (RA) sera and may be a product of inflammatory macrophages. Our objective was to compare the biochemical characteristics of TRACP 5a and 5b. METHODS: We transfected the human ACP 5 gene into CHO cells and cloned a stable cell line (CHO/TRACP 8F5) that expresses high levels of TRACP activity both intracellularly and as a secreted product. Both enzyme preparations were purified on an anti-TRACP antibody column. Their biochemical properties were compared to the natural serum isoforms using colorimetric assays for activity and total protein. Their structural properties were compared to natural serum isoforms using denaturing and nondenaturing polyacrylamide gel electrophoresis. RESULTS: Both enzyme preparations were heterogeneous. The combined secreted recombinant TRACPs (rTRACP(ex)) had all the characteristics of natural serum TRACP 5a. There were seven uncleaved glycoproteins with a pH optimum of 5.2, relatively low specific activity (278 U/mg) and differentially sialylated. The combined intracellular TRACPs (rTRACP(in)) had all the characteristics of natural serum TRACP 5b. They consisted of two proteins, one of which was a processed heterodimer, with a pH optimum of 5.8, a relatively high specific activity (887 U/mg) and lacked sialic acid. CONCLUSION: This cell line provides an avenue for the simultaneous study of the regulation, function and intracellular trafficking of separate TRACP isoforms and the identification of their physiologic substrates in a single uniform cell source.

4-Nitrophenylphosphatase↗

Zinc-ion-dependent acid phosphatase exhibits magnesium-ion-dependent myo-inositol-1-phosphatase activity.

We have purified bovine brain Zn(2+)-dependent acid phosphatase (Zn(2+)-APase), which requires Zn2+ ions to hydrolyze the substrate p-nitrophenyl phosphate (pNPP) in an acidic environment. The substrate specificity and metal requirement of Zn(2+)-APase at a physiological pH was also studied. The enzyme exhibited hydrolytic activity on myo-inositol-1- and -2-monophosphates, 2'-adenosine monophosphate, 2'-guanosine monophosphate, and the alpha- and beta-glycerophosphates, glucose-1-phosphate, and fructose-6-phosphate in 50 mM Tris-HCl buffer (pH 7.4) in the presence of Mg2+ ions, but not on pNPP and phosphotyrosine. Zn2+, Mn2+ and Co2+ ions were less effective for activation. Among the above substrates, myo-inositol-1-phosphate was the most susceptible to hydrolysis by the enzyme in the presence of 3 mM Mg2+ ions. The enzyme exhibited an optimum pH at around 8 for myo-inositol-1-phosphate in the presence of 3 mM Mg2+ ions. The Mg(2+)-dependent myo-inositol-1-phosphatase activity of the enzyme was significantly inhibited by Li+ ions. The Zn(2+)-dependent p-nitrophenyl phosphatase activity and Mg(2+)-dependent myo-inositol-1-phosphatase activity of the purified enzyme fraction exhibited similar behavior on Sephadex G-100 and Mono Q colomns. These findings suggest that Zn(2+)-APase also exhibits Mg(2+)-dependent myo-inositol-1-phosphatase activity under physiological conditions.

Acid Phosphatase↗

Similarities between gibberellins and related compounds in inducing Acid phosphatase and reducing sugar release from barley endosperm.

Barley endosperm halves release acid phosphatase in response to several gibberellins and gibberellin precursors. Seed halves incubated with 10(-7)m GA(3) at 29 degrees begin to release phosphatase after 11 hr and release it for another 26 hr in response to GA(3). After 37 hr, the rate of release slows to that of seed halves incubated without GA(3). GA(3) is active at 10(-10)m and maximally active at 10(-7)m. Comparative activity of 12 gibberellins and gibberellin precursors is GA(1) = GA(3) > GA(2) > GA(4) = GA(7) > GA(5) = GA(13) > GA(14) > GA(8) = GA(9) > (-)kaurenoic acid > (-)-kaurene. These compounds show the same order of activity and approximately the same relative activity in inducing reducing sugar release as in inducing phosphatase activity. The activity of each compound increases with its presumed position in a biosynthetic pathway leading from kaurene to GA(3). This correlation suggests that activity may be a reflection of the efficiency of conversion to an active form within the seed half.The ease of measuring the acid phosphatase response and the sensitivity of the seed halves to low concentrations of many gibberellins and gibberellin precursors makes this a useful bioassay for gibberellin-like substances.

Journal Article↗

Stability and activity of immobilized hydrolytic enzymes in two-liquid-phase systems: acid phosphatase, beta-glucosidase, and beta-fructofuranosidase entrapped in poly(2-hydroxyethyl methacrylate) matrices.

Enzyme storage stability and hydrolysis yield were measured in experiments carried out with three model hydrolytic enzymes: acid phosphatase (EC 3.1.3.2), beta-glucosidase (EC 3.2.1.4), and beta-fructofuranosidase (EC 3.2.1.26) entrapped in hydrogels of poly(2-hydroxyethyl methacrylate). Runs were performed at 30 degrees C, under intensive stirring (500 rev min-1), in 50% v/v biphasic media prepared with buffer and organic solvents, whose log P value varied from 0.68 to 8.8. Storage stability was also monitored in the pure solvents. The small average particle size (125-210 microns) and the intensive stirring eliminate hindrances of intra- and interphase mass transfer resistances. The hydrophilic matrix protects the enzymes against thermal and chemical deactivation, thus allowing good production per unit weight of biocatalyst. In biphasic media, storage stability, with the exception of acid phosphatase, was not dependent on solvent polarity. On the contrary, a significant trend was observed when the enzymes were stored in neat organic solvents.

Acid Phosphatase↗

Purification and some properties of tartrate-sensitive acid phosphatase from rabbit kidney cortex.

Two forms of tartrate-sensitive acid phosphatases (EC 3.1.3.2) were purified from rabbit kidney cortex by a multiple-column-chromatography method. The basic form constituted 90% of the enzyme and migrated as a single band of protein on polyacrylamide-gel electrophoresis. The proteins contaminating the acidic form did not exceed 5% of the total protein. The specific activity towards p-nitrophenyl phosphate was 12 mumol/min per mg for the basic form and 0.7 mumol/min per mg for the acidic form. The basic form of the enzyme differs from the acidic form in its heat-stability, Km values, inhibition rates by tartrate and fluoride and substrate specificities. Relative to p-nitrophenyl phosphate hydrolysis rate, the acidic form hydrolysed a variety of physiological monophosphate esters, whereas the basic form hydrolysed only CMP and phosphoenolpyruvate. Bacterial neuraminidases had no effect on the activity and mobility of the acidic form on polyacrylamide-gel electrophoresis. Both forms have the same molecular weight (101000 +/- 4000) and are probably composed of two identical subunits. The question whether the two forms of the enzyme are different proteins or whether one is a modified form of the other is discussed.

Acid Phosphatase↗

Acid phosphatase in the pathogenic and nonpathogenic hemoflagellates, Cryptobia spp., of fishes.

Acid phosphatase (ACP) was detected in whole-cell lysates, membrane-bound and water-soluble fractions of Cryptobia salmositica (pathogenic and nonpathogenic vaccine strains), Cryptobia bullocki, and Cryptobia catostomi using p-nitro-phenylphosphate as the substrate. High activities were in acidic pH (3.0-5.5) and the optimal pH was 5.0 Highest ACP activity was in the membrane-bound fraction. The pathogenic strain of C. salmositica had significantly higher total ACP activity than the vaccine strain and the other 2 species. However, the activity in the pathogenic C. salmositica decreased significantly with prolonged in vitro cultivation. The membrane-bound ACP of the pathogenic C. salmositica had highest resistance to the ACP inhibitor, sodium tartrate.

Acid Phosphatase↗

[Change in acid phosphatase and N-acetyl-beta-glucosaminidase activity in mouse lymphocytes induced by concanavalin A].

The treatment with concanavalin A (5 micrograms/ml) of mouse lymphocytes containing 70-72% of T cells entails an increase in the activity of acid phosphatase and a decrease in the activity of N-acetyl-beta-glucosaminidase. These changes were detectable 15 h after lymphocyte incubation with Con A. After 24 h of incubation acid phosphatase activity rose 2-fold whereas that of N-acetyl-beta-glucosaminidase dropped 45-50%. Possible mechanisms of these changes are discussed.

Acetylglucosaminidase↗

Localization of lysosomal acid phosphatase mRNA in mouse tissues.

We studied the expression of lysosomal acid phosphatase (LAP) in mouse by hybridizing Northern blots and tissue sections with the mouse LAP cDNA. Three mRNA species of 2.3, 3.2 and 5.2 KB were identified, which differ in the length of their 3' untranslated region (UTR). The 3.2 KB mRNA is expressed in equal amounts in all tissues and represents the major species in most tissues, whereas the amounts of the 2.3 and 5.2 KB species differ. In situ hybridization of different tissues of adult mice showed a uniform expression of LAP, as expected for a housekeeping gene, except in testis and brain. In testis we found an increase in the LAP mRNA level in spermatocytes. By Northern blot analysis of young mouse testis, this increase could be attributed to late pachytene primary spermatocytes or secondary spermatocytes. In brain tissue the neurons were predominantly labeled, especially the Purkinje and pyramidal cells, whereas glial cells expressed only low amounts of LAP mRNA. Very high LAP expression was also found in the epithelial cells of the choroid plexus. Analysis of LAP expression during mouse embryonic development between Days 9.5 and 17.5 revealed a prominent expression relative to other tissues in the neural tube from Day 9.5 to Day 13.5.

Acid Phosphatase↗