Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ACID PHOSPHATASE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,441 records · Page 80Linked to original sources

Three-dimensional structure of a mammalian purple acid phosphatase at 2.2 A resolution with a mu-(hydr)oxo bridged di-iron center.

The crystal structure of purple acid phosphatase from rat bone has been determined by molecular replacement and the structure has been refined to 2.2 A resolution to an R -factor of 21.3 % (R -free 26.5 %). The core of the enzyme consists of two seven-stranded mixed beta-sheets, with each sheet flanked by solvent-exposed alpha-helices on one side. The two sheets pack towards each other forming a beta-sandwich. The di-iron center, located at the bottom of the active-site pocket at one edge of the beta-sandwich, contains a mu-hydroxo or mu-oxo bridge and both metal ions are observed in an almost perfect octahedral coordination geometry. The electron density map indicates that a mu-(hydr)oxo bridge is found in the metal center and that at least one solvent molecule is located in the first coordination sphere of one of the metal ions. The crystallographic study of rat purple acid phosphatase reveals that the mammalian enzymes are very similar in overall structure to the plant enzymes in spite of only 18 % overall sequence identity. In particular, coordination and geometry of the iron cluster is preserved in both enzymes and comparison of the active-sites suggests a common mechanism for the mammalian and plant enzymes. However, significant differences are found in the architecture of the substrate binding pocket.

Acid Phosphatase↗

Aging and multiple forms of acid phosphatase in isolated rat liver cells.

Purified suspensions of highly viable parenchymal, endothelial and Kupffer cells were prepared from the livers of young (3 months of age) and old (33-34 months of age) female rats. In the cell suspensions, the activities of the multiple forms of acid phosphatase were determined with the substrates 4-methylumbelliferyl phosphate, 1-naphthyl phosphate and p-nitrophenyl phosphate. Most specific enzyme activities increased during aging, but the preference to hydrolyse any of the three substrates did not change. The small age-related changes in effects of the inhibitors fluoride and alloxan were not uniform for the the three liver cell types. The pattern for multiple forms of acid phosphatase obtained after isoelectric focusing did not change with age for Kupffer cells, while one of the two major forms of the enzyme almost disappeared in endothelial cells from old rats. With age, a very pronounced heterogeneous pattern was observed for the enzyme forms in the long-lived parenchymal cells. The increase in heterogeneity in multiple forms of acid phosphatase in aging parenchymal cells may be the result of post-translational modifications.

Acid Phosphatase↗

Endogenous expression and endocytosis of tartrate-resistant acid phosphatase (TRACP) by osteoblast-like cells.

Tartrate-resistant acid phosphatase (TRACP) is produced by macrophages and other cells of the monohistiocytic lineage. In particular, osteoclasts are characterized for a high expression of this enzyme. Yet, several data suggest that other bone cell types, such as osteocytes and osteoblasts, may also express activity of this enzyme. This is particularly obvious at sites were osteoclasts resorb bone, suggesting that osteoclasts (or their precursors) somehow induce TRACP activity in osteoblasts. In the present study, we investigated this by culturing human osteoblast-like cells with and without conditioned medium (MCM) from human blood monocytes (as a source of osteoclast precursors). High levels of TRACP activity were found in osteoblast-like cells cultured with MCM. Depletion of TRACP from this medium resulted in the absence of its activity in osteoblast-like cells, thus suggesting that the TRACP activity in these cells was the result of endocytosed TRACP that was released by the monocytes in the MCM. Osteoblast-like cells cultured in control (non-conditioned) medium contained very low levels of TRACP-like activity. However, the cells expressed TRACP mRNA and incubation of extracts of these cells with active cathepsin B did induce activity of a TRACP-like enzyme. Inhibition of the activity of cysteine proteinases in general and of cathepsin B in particular, completely blocked TRACP activity of the osteoblast-like cells. This TRACP-like enzyme but not the alleged endocytosed fraction of TRACP was inhibited by fluoride, suggesting that the fractions may be different isoenzymes. Our data seem to indicate that osteoblast-like cells may contain two different fractions of TRACP, one that is released by monocytes and subsequently endocytosed by osteoblast-like cells and a second endogenous fraction that is present in an inactive proform. We hypothesize that the capacity of osteoblast-like cells to endocytose TRACP is important for the removal of this enzyme during or following the bone resorptive activity of the osteoclast.

Acid Phosphatase↗

Identification of active-site residues in Aspergillus ficuum extracellular pH 2.5 optimum acid phosphatase.

Primary structure elucidation of peptides generated by cyanogen bromide, endoproteinase Glu-C, and clostripain cleavage of an Aspergillus ficuum extracellular pH optimum 2.5 acid phosphatase identified a region which contains the active site of the enzyme. The 23-residue segment contains the fragment RHGXRXP, which is homologous to acid phosphatase from Saccharomyces spp., Aspergillus ficuum, mammals, and bacteria. Homologous or conservative substitutions are observed in the 10-amino acid fragment preceding this region.

Acid Phosphatase↗

Analysis of distinct tartrate-resistant acid phosphatase promoter regions in transgenic mice.

The tartrate-resistant acid phosphatase (TRAP) is present in multiple tissues, including kidney, liver, lung, spleen, and bone. Recent study of (TRAP) gene expression has provided evidence for distinct promoters within the (TRAP) gene, suggesting that the gene has alternative, tissue-preferred mRNA transcripts. Examination of endogenous (TRAP) exon 1B and 1C mRNA transcripts revealed tissue-preferred transcript abundance with increased exon 1B transcripts detected in liver and kidney and increased exon 1C transcripts detected in bone and spleen. In this investigation, we have made transgenic mice that express a marker gene driven by two candidate promoters, designated BC and C, within the (TRAP) gene. The BC and C promoters are 2.2 and 1.6 kb, respectively, measured from the translation initiation site. Evaluation of BC transgenic lines demonstrated robust expression in multiple tissues. In contrast, significant transgene expression was not detected in C transgenic lines. Evaluation of transgene mRNAs in BC transgenic lines revealed that virtually all expression was in the form of B transcripts, suggesting that the tissue-preferred pattern of endogenous (TRAP) was not replicated in the BC transgenic line. Likewise, osteoclastogenic cultures from BC, but not C, transgenic bone marrow cells expressed the transgene following receptor activator of NFkappaB ligand/macrophage colony-stimulating factor stimulation. In conclusion, when compared with the 2.2-kb BC portion of the (TRAP) promoter region, the 1.6-kb C portion does not account for significant gene expression in vivo or in vitro; production of the bone- and spleen-preferred (TRAP) C transcript must depend on regulatory elements outside of the 2.2-kb promoter. As the majority of currently investigated transcription factors that influence transcriptional regulation of osteoclast gene expression bind within the 1.6-kb C portion of the (TRAP) promoter, it is likely that transcription binding sites outside of the 2.2-kb region will have profound effects on regulation of the gene in vivo and in vitro.

Acid Phosphatase↗

Diagnostic value of leucocytic acid-phosphatase isoenzymes in determining cytological types of non-lymphoid acute leukaemias.

The normal isoenzymatic pattern of leucocytic acid-phosphatase based on the study of 150 haematologically normal individuals is reported. The different pathologic patterns of the leucocytic acid-phosphatase isoenzymes occurring in non-lymphoblastic acute leukaemias are presented and correlated with the subdivisions of acute leukaemias established by the French-American-British (FAB) Co-operative Group. This study is considered to be especially useful in identifying pure acute monocytic leukaemias corresponding to subtype M5 of the FAB as well as acute erythraemias with unusual cytological and cytochemical features.

Acid Phosphatase↗

Simple, rapid determination of zinc and acid phosphatase in seminal plasma with an ABA-100 bichromatic analyzer.

I describe an automated assay for zinc and acid phosphatase in seminal plasma. These, which are markers of the function of the prostate, were assayed bichromatically with an Abbott ABA-100 analyzer. As many as 25 samples of human seminal plasma can be analyzed sequentially with CVs of 3.1% for zinc and 1.5% for acid phosphatase. The sensitivity, specificity, and speed of this assay system make it practicable for use in investigation of male infertility.

Acid Phosphatase↗

Erythrocyte acid phosphatase (ACP1) activity. In vitro modulation by adenosine and inosine and effects of adenosine deaminase (ADA) polymorphism.

Erythrocyte acid phosphatase (ACP1) activity was determined in the absence of modulators and in the presence of either adenosine or inosine as modulators in 154 samples of red blood cells collected from adult donors. Adenosine and inosine showed modulating effects (activation), that were genotype dependent in the allele order pb less than pa less than pc; the activation by inosine was much higher than by adenosine. The modulating effect was dependent on adenosine deaminase (ADA) genotype: In carriers of ADA2 allele the activation with ACP1 phenotype A was lower and that with phenotypes CA and CB was higher than in ADA1/ADA1 subjects. In addition, the basic ACP1 activity (i.e., without modulators) also appeared to be dependent on ADA genotype: The lowest ACP1 activity was observed in A and BA subjects carrying the ADA2 allele. Since the deamination of adenosine to inosine associated with ADA2-1 phenotype is slower than that associated with ADA1, the interaction of ADA on ACP1 activity may in fact be explained by a lower intracellular concentration of inosine in ADA2 carriers and, therefore, by a lower modulating effect of this on acid phosphatase activity.

Acid Phosphatase↗

Different tartrate sensitivity and pH optimum for two isoenzymes of acid phosphatase in osteoclasts. An electron-microscopic enzyme-cytochemical study.

By differentiation of substrate specificity, pH optimum range, and sensitivity to various inhibitors, 2 isoenzymes of acid phosphatase in bone cells have been studied at the electron-microscopic level. When p-nitrophenyl phosphate was used for the substrate, the demonstrable enzyme activity was affected by neither tartrate nor sodium fluoride. The reaction product, when incubated at pH 5-6, was detected in all sites along the pathway for the biosynthesis of acid phosphatase in the osteoclast, including the perinuclear space, cisternae of the endoplasmic reticulum, Golgi complex, various vesicles, and vacuoles. In the osteoclasts attached to bone, the enzymatic activity was demonstrated at the extracellular ruffled border and on the eroded bone surface. Reaction products became confined to lysosomes and extracellular ruffled border when incubated at pH 6-7. Unattached osteoclasts showed a similar intracytoplasmic localization of enzyme as the attached ones, except for the absence of the extracellular enzyme activity. The mononuclear, immature type of osteoclast also resembled the mature osteoclast in terms of enzymatic localization. Except for the osteoclasts, the acid p-nitrophenyl phosphatase activity was restricted to lysosomal vesicles in various bone cells, monocytes, and macrophages. Such activity was inhibited by adding 50 mM tartrate to the p-nitrophenyl phosphate medium. When beta-glycerophosphate or p-nitrocatechol sulfate was the substrate, most of the reaction product was localized intracellularly. Unlike the acid p-nitrophenyl phosphatase, the acid beta-glycerophosphatase or arylsulfatase activity in osteoclasts and other bone cells was inhibited completely by 10 mM tartrate or 10 mM sodium fluoride.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗

Quantitative determination of acid phosphatase activity detected in tissue sections according to the Burstone method.

Quantitative determination of the activity of acid phosphatase detected in tissue sections using Burstone's method. The experiment was performed on inbred rats. A reaction for AcP according to Burstone was made in liver sections, incubation time was fixed experimentally. The material obtained from each animal was divided into 3 parts. One of them was used for enzymatic estimations, the 2nd for planimetry of sections, and the 3rd was eluted by N,N-dimethylformanid, and the obtained coloured product was subjected to spectrophotometric analysis at the Spectrophotometer Unicam SP 8000 B. Homogeneity of the coloured product eluted from the sections as well as its identity with the coloured product obtained during the reaction with a preparation of crystalline acid phosphatase was found. Repeatability of the obtained activity for the inbred animals was shown. The obtained results were subjected to statistical analysis. The method of quantitative estimation of AcP activity may be useful in histoenzymatic works.

Acid Phosphatase↗

Characterization of the principal human prostatic acid phosphatase isoenzyme, purified by affinity chromatography and isoelectric focusing. Part II.

The principal enzyme of human prostatic acid phosphatase [orthophosphoric monoester phosphohydrolase (acid optimum), EC 3.1.3.2], which had been highly purified by affinity chromatography, isoelectric focusing, and gel filtrations, was shown to be homogeneous at pH 5.0 by sedimentation equilibrium analysis. The amino acid composition was determined and the sedimentation coefficient of the native molecule measured. The relative molecular mass was 89,000 at pH 5.0, as measured by analytical ultracentrifugation. The Km-value of the enzyme for p-nitrophenyl phosphate as substrate is 1.8-10(-4) mol/liter. I also examined substrate speificity, different inhibitors, and the effects of pH, temperature, and serum on the enzyme activity.

Acid Phosphatase↗

Acid phosphatase and alpha-naphthyl acetate esterase in neoplastic and non-neoplastic lymphocytes. A statistical analysis.

Acid phosphatase and alpha-naphthyl acetate esterase reaction patterns were evaluated in lymphocytes from patients with a variety of neoplastic and non-neoplastic conditions: leukemia, 59; NHL, 53; and reactive follicular hyperplasia, 23. Fifteen individuals with normal peripheral blood were also studied. For both enzymes, statistical analysis showed a strong correlation between a globular reaction pattern and T lymphocytic origin in both non-neoplastic lymph nodes and normal peripheral blood specimens (P less than 0.0001). A similarly strong correlation was found between a granular acid phosphatase pattern and T lymphocytic origin in cell isolated from non-neoplastic lymph nodes (P less than 0.0001) but not in those obtained from normal peripheral blood where this pattern was observed with equal frequency in B, T, and "null" lymphocytes (P = 0.415). A granular alpha-naphthyl acetate esterase pattern was correlated with non-T lymphocytes from normal peripheral blood (P less than 0.0001), but was observed with equal frequency in B, T, and "null" lymphocytes fron non-neoplastic lymph nodes (P = 0.76). In the eight T cell neoplasias studied, a globular pattern was evident in the majority of cells for both enzymes. In the majority of the B cell neoplasias, however, a granular pattern was observed for both enzymes.

Acid Phosphatase↗

[Enzymatic tests for alkaline and acid phosphatase in gingival tissues in workers of the Chelm Cement Plant].

Using histochemical methods the activity of alkaline and acid phosphatase was determined in the gingivae of 38 workers aged from 26 to 59 years employed in work with greatest exposure to dust. The control group comprised 11 men aged 23 to 49 years living in Chelm or in its vicinity, not exposed to cement dust. The activity of alkaline phosphatase in the group with exposure and with deep gingivitis of lower intensity was very high, while it was lower in the group with highest intensity of the inflammatory process. The activity of acid phosphatase increased with increasing intensity of pathological changes.

Acid Phosphatase↗

[Lipid peroxidation, the enzyme antioxidative system and acid phosphatase content of the gastric mucosa in stomach ulcer].

Lipid peroxidation, a state of the antioxidative system and activity of acid phosphatase were studied in mucosal membrane of 53 patients with ulcerous disease of stomach. Increase of the acid phosphatase activity in cytoplasm, activation of lipid peroxidation and inhibition of the antioxidative system were detected in ulcer border and periulcerous region. These alterations in lipid peroxidation and the state of the antioxidative system were considered as distinct pathogenetic factors responsible for deterioration of lysosomal membranes and contributing to chronic and relapsing development of ulcerous disease.

Acid Phosphatase↗

Stimulated intraphagosomal release of eosinophil peroxidase and acid phosphatase in the rats spontaneously infected with Mycoplasma pulmonis: a cytochemical study.

In this study we performed a cytochemical comparison of peroxidase and acid phosphatase activities in peritoneal eosinophils from specific pathogen-free (SPF) and Mycoplasma pulmonis-infected rats. When eosinophils ingested polystyrene particles for 120 min, peroxidase- and acid phosphatase-positive specific granules, as well as small granules, fused to phagosomes. Unusual peroxidase activity was detected in some particle-containing phagosomes in 6.8% of eosinophils from control SPF rats and 31% of those from infected rats. Intense acid phosphatase activity was also demonstrated in some phagosomes in 4 and 20% of eosinophils from control and infected rats, respectively. The rate of peroxidase-positive and acid phosphatase-positive phagosomes to all ingested phagosomes was 8.1 and 7.3% in control rats and rose to 41.3 and 31.1% in those infected, respectively. The population of eosinophils (18%) in the control peritoneal cells did not change after infection (16.6%). These results suggest that the intraphagosomal release of lysosomal enzymes was significantly stimulated in peritoneal eosinophils of the rats spontaneously infected with M. pulmonis.

Acid Phosphatase↗

Genetic control of acid phosphatase Rm and its relation to control of peroxidase Rm in flax (Linum) genotrophs.

Evidence from various workers has indicated that isozyme relative mobility (Rm) may not be defined solely by the corresponding structural gene but may also be modified by alleles at other loci. The instances of numerous, small ongoing temporal or tissue changes in Rm for certain enzyme systems in plants may be another aspect of this modification due to interactions between genes. A further possible example of Rm modification occurs in connection with environmentally (fertilizer treatment) induced heritable changes within particular completely inbred and genetically homogeneous plant genotypes. Fertilizer-induced, persistent relative mobility (Rm) shifts for peroxidases are controlled by two alleles at one locus, a dominant for faster Rm and a recessive for slower Rm; codominance is completely absent. There are similar Rm shifts in acid phosphatases, likewise stemming from molecular weight changes. This study examined genetic control of the acid phosphatase Rm shift and its relation to peroxidase Rm control. It showed that the environmentally induced heritable acid phosphatase Rm shift is controlled by an identical system of a dominant (faster) and recessive (slower) allele, closely linked to the locus controlling peroxidases. The Rm shifts for both these enzyme glycoproteins are unidirectional, with no codominance; at least 10 other nonidentified glycoproteins display the same unidirectional Rm shifts. The results suggest modification, possibly posttranslational or transcriptional, controlled by modifier loci. This supports indications in other organisms that small numbers of modifier loci may control widespread Rm changes in the protein products of a genome.

Acid Phosphatase↗

Structure and function of the PHO82-pho4 locus controlling the synthesis of repressible acid phosphatase of Saccharomyces cerevisiae.

pho4 mutants of Saccharomyces cerevisiae, although rare among phosphatase-negative mutants isolated from wild-type strains, were isolated efficiently from pho80, pho85, or pho80 pho85 strains. The distribution of these pho4 mutants over the pho4 locus was determined by analyzing random spores of two- and three-factor crosses. The pho4-4 mutation confers temperature-sensitive synthesis of repressible acid phosphatase. An intragenic suppressor for the pho4-12 allele results in the temperature-sensitive synthesis of repressible acid phosphatase. Recombination between these sites occurs at 1.0 to 3.0%, the highest for any pair of sites within the pho4 locus. All these results strongly indicate that the information of the pho4 locus is translated into a protein. The PHO82 site was mapped inside the pho4 locus by random spore analysis. The order met10-pho4-1PHO82-1-pho4-9 on the right arm of chromosome VI was confirmed by tetrad analysis. Doubly heterozygous diploids, pho3 PHO82c PHO4+/pho3 pho82+ pho4, produce variable amounts of repressible acid phosphatase under repressive conditions depending on the combination of PHO82c and pho4 alleles. This phenomenon may reflect the constitutive production of the pho82+-pho4 product in the repressed condition, which interferes with the function of the PHO82c-PHO4+ product. The earlier model for the function of the PHO82-pho4 cluster, in which the PHO82 site acts as an operator of the pho4 gene, has been revised to a model in which the PHO82 site codes for the part of the pho4 protein that has affinity for the regulatory protein encoded by the pho80 and pho85 genes.

Acid Phosphatase↗