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Enzyme histochemical studies of acid phosphatase isoenzymes in induced heterotopic bone formation in guinea pigs.

A bone induction model was used to study the effect of different pretreatments and inhibitors added to the substrate media used for the histochemical demonstration of acid phosphatase activity. Two different acid phosphatases (AcP) were demonstrated. The AcP of matrix-producing cells exhibited resistance to pretreatment with EDTA while it was sensitive to tartrate added to the incubation medium. The AcP in dentin resorbing cells was EDTA sensitive but resistant to tartrate. The AcP activities in both resorbing and matrix-producing cells generally sensitive to fluoride, copper and molybdate. In some of the dentinoclasts, fluoride resistant AcP was observed. The results suggest previous investigations on normal bone formation, suggesting that at least two different isoenzymes of AcP exist. One of these seemed to be related to matrix production and mineralization of the new heterotopic bone.

Acid Phosphatase↗

A possible rôle for acid phosphatase in gamma-amino-n-butyrate uptake in Aspergillus nidulans.

Previously published work from another laboratory has shown that the mutation pacC-5 in the ascomycete Aspergillus nidulans leads to loss of an acid phosphatase (EC 3.1.3.2) activity and is probably located in the structural gene for this enzyme. Here, we show that, pleiotropically, pacC-5 considerably reduces gamma-amino-n-butyrate transport levels as shown both by direct uptake measurements and two kinds of growth tests. A reduction in expression of the permease specified by the gabA gene is almost certainly responsible for the gamma-amino-n-butyrate uptake defect in pacC-5 strains. pacC-5 does not reduce L-proline uptake, mainly mediated by the prnB permease, or beta-alanine uptake. This work and our previously published results suggest that, although it does not uniquely reduce gamma-amino-n-butyrate uptake, pacC-5 is highly selective in its effects on transport processes. It is therefore probable that the acid phosphatase specified by the pacC gene plays some rôle in the synthesis, membrane integration or functioning of a particular class of permeases. A rôle for acid phosphatases in membrane processes casts an intriguing new light on the fact that these enzymes are periplasmic and extracellular in many micro-organisms including A. nidulans.

Acid Phosphatase↗

Posttranslational regulation of repressible acid phosphatase in yeast.

On the basis of genetic data it has been suggested that repressible acid phosphatase of Saccharomyces cerevisiae is regulated by a control circuit involving operator-repressor mechanisms (Toh-e et al., 1978). We measured no significant difference in the amount of translatable mRNA of repressed and derepressed cells in the reticulocyte in vitro translation system. We find a 25 fold difference in specific enzyme activity in repressed versus derepressed cells whereas the amount of 35S-methionine labelled enzyme protein as measured by antibody precipitation varies only 2-3 fold. This argues for posttranslational regulation of preexisting inactive acid phosphatase. Minor regulatory effects at the transcriptional or translational level cannot be excluded.

Acid Phosphatase↗

Localisation of vitronectin receptor immunoreactivity and tartrate resistant acid phosphatase activity in synovium from patients with inflammatory or degenerative arthritis.

The influx of cells into the synovial intima in rheumatoid joints may include osteoclasts and their precursors. The distribution of osteoclast markers--namely, tartrate resistant acid phosphatase activity and the expression of vitronectin receptor (shown with monoclonal antibodies 13C2 and 23C6)--was therefore examined in synovium obtained from patients with rheumatoid (RA) or degenerative (OA) arthritis. Tartrate resistant acid phosphatase positive cells were found in frozen sections of 60% (n = 30) of RA and 69% (n = 29) of OA synovial membranes. Whereas all synovia tested (four RA, four OA) showed diffuse staining of the lining cells with 13C2, 55% (n = 11) of RA and 57% (n = 14) of OA synovial membranes contained isolated cells stained with 23C6 scattered throughout the tissue. In cultures of synovial cells, tartrate resistant acid phosphatase positive, multinuclear, and 23C6 positive cells were found; these cells did not, however, form resorption pits on bone slices. The results show that fully differentiated osteoclasts are uncommon in synovium from patients with either degenerative or inflammatory arthropathies.

Acid Phosphatase↗

A radioimmunoassay for prostatic acid phosphatase.

A solid phase radioimmunoassay for human prostatic acid phosphatase has demonstrated substantially greater biochemical sensitivity than a standard enzymatic method for which p-nitrophenylphosphate was used as substrate. Preliminary data indicate that the radioimmunochemical approach can precisely classify 43% stage I-II and 94% stage III-IV prostate cancers. In contrast, the standard enzymatic methods correctly classified only 9% stage I-II and 46% stage III-IV cancers. It is clinically apparent that a radioimmunochemical approach for the measurement of human prostatic phosphatase may have distinct potential in the clinical diagnosis of prostate cancer.

Acid Phosphatase↗

Digestion and the distribution of acid phosphatase in Blepharisma.

Suspensions of Blepharisma intermedium were fed latex particles for 5 min and then were separated from the particles by filtration. Samples were fixed at intervals after separation and incubated to demonstrate acid phosphatase activity. They were subsequently embedded and sectioned for electron microscopy. During formation of the food vacuole, the vacuolar membrane is acid phosphatase-negative. Within 5 min, dumbbell-shaped acid phosphatase-positive bodies, possibly derived from the the acid phosphatase-positive Golgi apparatus, apparently fuse with the food vacuole and render it acid phosphatase-positive. A larger type of acid phosphatase-positive, vacuolated body may also fuse with the food vacuole at later stages. At about 20 min after formation, acid phosphatase-positive secondary pinocytotic vesicles pinch off from the food vacuoles and approach a separate system of membrane-bounded spaces. By 1 hr after formation, the food vacuole becomes acid phosphatase-negative, and the undigested latex particles are voided into the membrane-bounded spaces. The membrane-bounded spaces are closely associated with the food vacuole at all stages of digestion and are generally acid phosphatase-negative. Within the membrane-bounded spaces, dense, pleomorphic, granular bodies are found, in which are embedded mitochondria, paraglycogen granules, membrane-limited acid phosphatase-containing structures, and Golgi apparatuses. The granular bodies may serve as vehicles for the transport of organelles through the extensive, ramifying membrane-bounded spaces.

Acid Phosphatase↗

Molecular analysis of the Salmonella typhimurium phoN gene, which encodes nonspecific acid phosphatase.

The phoN gene of Salmonella typhimurium encodes nonspecific acid phosphatase (EC 3.1.3.2), which is regulated by a two-component regulatory system consisting of the phoP and phoQ genes. We cloned the phoN region into a plasmid vector by complementation of a phoN mutant strain and determined the nucleotide sequence of the phoN gene and its flanking regions. The phoN gene could encode a 26-kDa protein, which was identified by the maxicell method as the product of phoN. Results of the enzyme assay and Southern hybridization with chromosomal DNA of Escherichia coli K-12 suggests that there is no phoN gene in E. coli. The regulatory pattern of phoN in E. coli and Southern hybridization analysis of the E. coli chromosome with the S. typhimurium phoP gene suggest that E. coli K-12 also harbors the phoP and phoQ genes.

Acid Phosphatase↗

Immunological and colorimetric determination of prostatic acid phosphatase--technical and clinical reappraisal in symptomatic patients.

We compared a selection of quantitative immunological methods for prostatic acid phosphatase (PAP) with routine colorimetric assays for total and tartrate-labile acid phosphatase and evaluated their relative clinical merits in the differential diagnosis of prostatic carcinoma. We also assessed a wide range of commercial control materials for suitability of use with these methods. Patients studied included 111 cases of prostatic carcinoma, 42 cases of benign prostatic hyperplasia, and 33 controls. The principles of the methods used included determination of enzymatic activity using p-nitrophenyl phosphate, RIA, immunoradiometric, and enzymoimmunometric assays. Performance characteristics for the immunological methods were inferior to manufacturers' precision and specificity claims. We identified control materials that were unsuitable for routine use. Poor discrimination between clinical groups was observed for all methods. Analysis by use of a receiver operator characteristic plot failed to improve this. We conclude that the immunological methods we studied offer no advantages over colorimetric methods in the differential diagnosis of prostatic cancer in symptomatic patients.

Acid Phosphatase↗

Effect of endotoxin on rat liver. Analysis of acid phosphatase isozymes in the liver of normal and endotoxin-treated rats.

Lysosomal enzymes in parenchymal and sinusoidal cells in rat liver were sequentially studied following administration of endotoxin and correlated with fine structural changes in liver cells. In normal rat liver, there are three types of acid phosphatase isozymes, two present only in parenchymal cells and the other specifically in sinusoidal cells. The parenchymal acid phosphatase isozymes hydrolyze preferentially AMP and CMP, while the sinusoidal isozyme hydrolyzes phenylphosphate. After an intraperitoneal injection of an LD50 dose of endotoxin, the activity of the sinusoidal acid phosphatase isozyme reached a maximum at 1 hour, and was followed by an elevation of the activity of the isozymes derived from parenchymal cells. Within 1 hour after the injection, morphologic changes were most prominent within sinusoids, including swelling of the Kupffer cells and accumulation of polymorphonuclear leukocytes, platelets, and fibrin clumps on and around the Kupffer cells. Degenerative changes in parenchymal cells were observed following the initial reactions within sinusoids. The results of the present study are compatible with the hypothesis that the hepatic parenchymal cell damage induced by endotoxin is mediated by the initial changes within sinusoids, rather than by the direct aciton of endotoxin on the parenchymal cells.

Acid Phosphatase↗

Lymphoblastic lymphoma of convoluted or acid phosphatase type-a tumor of T precursor cells.

Five lymphatic neoplasms with strong focal acid phosphatase reactivity were selected from a group of acute lymphocytic leukemias and lymphoblastic lymphomas. All five cases showed an anterior mediastinal mass and exhibited identical morphology. This type of lymphoma has been described by Lukes under the term "malignant lymphoma of convoluted lymphocytes". Analysis of surface membrane receptors revealed that the tumor cells lacked surface immunoglobulin and receptors for Fc-fragment, but possessed receptors for complement (C3), untreated SRBC (ES) and SRBC treated with neuraminidase (ESN). By applying a mixed rosette assay using nucleated chicken erythrocytes coated with antibodies and C3, and denucleated ESN, it was found that a considerable number of tumor cells in all five cases formed mixed rosettes, i.e. that they bore the C3 receptor characteristic of B cells and simultaneously the E receptor characteristic of T cells. Thus the tumor cells resembled immature thymocytes of 10-15 weeks' gestation, which also show focal acid phosphatase reactivity and simultaneous expression of C3 and E receptors.

Acid Phosphatase↗

Stable acid phosphatase: I. Demonstration and distribution.

After a pH-dependent reactivation a highly stable form of acid phosphatase (SAPhase) could be demonstrated in active cells of the macrophage/giant cell/osteoclast series and also in epiphyseal chondrocytes, in cells lining bone undergoing resorption and in hamster eosinophils. Because acid phosphatases of epithelial cells in rat, hamster and Macaca sp. tissues did not possess this stability, SAPhase served as a useful cell marker for the above mesenchymal cell types in paraffin and glycol-methacylate sections even after rapid demineralization in acidic buffers. Conformational alterations appear to occur in the enzyme during formaldehyde fixation, embedding, and reactivation. The granular staining of SAPhase and the successful use of a non-aqueous fixative suggest an association of SAPhase with lysosomes and their membranes. Cells of mesencymal origin that are actively engaged in intra- and/or extracellular digestion contain high levels of SAPhase. The distribution and properties of SAPhase indicate an interrelationship between mononuclear and mutinuclear cell types actively engaged in such digestive processes.

Acid Phosphatase↗

Expression of tartrate-resistant acid phosphatase in bone marrow macrophages.

Bone marrow macrophages were found to express tartrate-resistant acid phosphatase (TRAP) under pathological conditions. In chronic granulocytic leukemia and metastatic carcinoma in the bone marrow this phenomenon was striking, all or almost all of the marrow macrophages being reactive. In other conditions, such as hypertransfusion or chemotherapy-induced marrow aplasia, the phenomenon did occur but was clearly a minor one. These observations indicate that tissue macrophages may become TRAP positive under the effect of unknown stimuli operating in certain pathological conditions. The results further suggest that the synthesis of the isoenzyme of acid phosphatase resistant to tartrate inhibition is a marker of macrophage activation rather than of differentiation towards particular subsets of the mononuclear phagocyte system.

Acid Phosphatase↗

Immunofluorescent identification of antibodies specific for prostatic acid phosphatase.

Antisera demonstrated by precipitation and passive haemagglutination to possess antibodies specific for prostatic tissue-specific acid phosphatase have been employed to localize this isoenzyme in the prostate by indirect immunofluorescence. Antisera specific for prostatic acid phosphatase may permit the immunohistological localization of this enzyme, thereby serving as a biological marker for metastatic prostatic cancer, where histological and/or clinical staging of the primary tumour remain uncertain.

Acid Phosphatase↗

Immunohistological localization of prostatic acid phosphatase.

Antisera demonstrated by precipitation and passive haemagglutination to posses antibodies specific for prostatic tissue-specific acid phosphatase have been employed to localize this isoenzyme in the prostate by indirect immunofluorescence. Antisera specific for prostatic acid phosphatase may permit the immunohistologic identification of this enzyme, thereby serving as a biological marker for metastatic prostatic cancer, where histological and/or clinical staging of the primary tumour remains questionable.

Acid Phosphatase↗

Suicide inactivation of human prostatic acid phosphatase and a phosphotyrosine phosphatase.

4-Difluoromethylphenyl bis(cyclohexylammonium) phosphate was synthesized in 4 steps starting from dibenzyl phosphite and shown to be a time-dependent suicide inactivator of human prostatic acid phosphatase and the SHP protein tyrosine phosphatase. The inactivation of human prostatic acid phosphatase followed pseudo-first-order kinetics with inactivation constants of Ki = 1.0 mM; ki = 0.15 min-1 (t1/2 = 4.6 min at saturation). Phenyl phosphate protected the enzyme against inactivation, indicating that inactivation occurs in the active site. The inactivation of SHP also followed pseudo-first-order kinetics, with a t1/2 = approximately 15 min in the presence of 8.2 mM inhibitor. The mechanism of inactivation likely involves the enzymatic release of difluoromethyl phenol which rapidly eliminates fluoride, generating a quinone methide. This potent electrophile then reacts with residues at the active site of the enzyme. This inhibitor and peptidic derivatives thereof have excellent potential for selective inactivation and labeling of protein tyrosine phosphatases.

Acid Phosphatase↗

Evaluation of a kinetic method for prostatic acid phosphatase with use of self-indicating substrate, 2,6-dichloro-4-nitrophenyl phosphate.

The purity, spectral characteristics, and rate of nonenzymatic hydrolysis of 2,6-dichloro-4-nitrophenyl phosphate (DCNPP) were determined. Rates of DCNPP hydrolysis by prostatic acid phosphatase (PAP) and erythrocytic acid phosphatase (EAP) (both EC 3.1.3.2) were measured in the absence and in the presence of various alcohols. 1.5-Pentanediol was the most effective transphosphorylation agent for specifically enhancing the activity of PAP. 1,4-Butanediol also enhanced PAP activity but markedly inhibited EAP activity. Bovine and human serum albumin preparations also accelerated the hydrolysis of DCNPP. DCNPP can be used for the continuous or multipoint-rate assay of PAP.

Acid Phosphatase↗

Golgi apparatus and acid phosphatase in mammary gland and kidney cells under the influence of diethylstilbestrol (DES).

It is commonly accepted that hormonal disturbances in experimental animals produce pathological changes in several organs namely in mammary glands and kidney. Taking into consideration the close relationship between acid phosphatase and Golgi apparatus, the present study was undertaken, to study the relationship in kidney and mammary gland cells under the influence of DES. The observation indicate, that acid phosphatase and Golgi apparatus were localized in the cytoplasm of mammary gland and kidney cells. It has also been found a parallel change in the activity of acid phosphatase and the degree of development of Golgi apparatus after DES administration.

Acid Phosphatase↗

Arylsulphatase and acid phosphatase activity associated with developing and ripe spermatozoa of the mussel Mytilus edulis.

Arylsulphatase and acid phosphatase activity were demonstrated cytochemically in spermatozoa of the marine mussel Mytilus edulis. Reaction product resulting from arylsulphatase activity was measured using an integrating microdensitometer and found to increase with incubation time and to be variable according to the pH of the incubation medium. Two peaks in activity, at pH 4.5 and 6.0 were evident for some experimental protocols suggesting the possibility of two isoenzymes; however, studies on the ultrastructural localization of the enzyme showed no difference between sites of activity for the two pH values. Ultrastructural localization of arylsulphatase showed activity associated with the Golgi body of developing spermatids and in particular within the proacrosomal vesicles but limited to the periphery of the acrosomal vesicle which is formed with the fusion of the proacrosomal vesicles. In spawned spermatozoa arylsulphatase activity was localized in association with the axial rod and subacrosomal material; activity also occurred along the outer acrosomal membrane and within the acrosomal vesicle and also associated with the acrosomal process following the acrosome reaction. Sulphate groups were demonstrated cytochemically within the vitelline coat of oocytes in the mantle tissue. These findings suggest that arylsulphatase could be one of the lysins previously demonstrated in M. edulis spermatozoa. Acid phosphatase activity was demonstrated in spawned spermatozoa around the nuclear envelope and along the outer acrosomal membrane.

Acid Phosphatase↗