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 1,549 records · Page 86Linked to original sources
PubMed1997

Induction of tissue-specific autoimmune prostatitis with prostatic acid phosphatase immunization: implications for immunotherapy of prostate cancer.

Prostatic acid phosphatase (PAP) is uniquely expressed in prostatic tissue and prostate cancer. In this study, the immunogenicity of PAP was investigated in a male rat model. We show that immunization with recombinant rat or human PAP in CFA leads to a significant Ab response, but does not generate CTL or result in autoimmune prostatitis. In contrast, immunization with recombinant vaccinia expressing human PAP, but not rat PAP, generates a CTL response and tissue-specific prostatitis in the absence of detectable PAP-specific Abs. These findings suggest that a cellular immune response to PAP, rather than Abs, mediates destructive autoimmune prostatitis. Thus, xenogeneic forms of PAP are a new tool for the induction of prostate-specific immunity and may prove useful for the immunotherapy of prostate cancer.

Acid Phosphatase↗
PubMed2004

Positive cooperativity in substrate binding of human prostatic acid phosphatase entrapped in AOT-isooctane-water reverse micelles.

The kinetics of 1-naphthyl phosphate and phenyl phosphate hydrolysis, catalyzed by human prostatic acid phosphatase (PAP) entrapped in AOT-isooctane-water reverse micelles, has been studied over surfactant hydration degree (w0) range 5 to 35. Continuous spectrophotometric acid phosphatase assays, previously prepared, were employed. PAP was catalytically active over the whole w0 studied range. In order to determine steady-state reaction constants the experimental data were fitted to Hill rate equation. Positive cooperativity in substrate binding was observed, as it was earlier found in aqueous solutions. The extent of cooperativity (expressed as the value of the Hill cooperation coefficient h) increased from 1 to 4, when the micellar water-pool size was growing, at fixed enzyme concentration. In the plots of catalytic activity (kcat) versus w0, the maxima have been found at w0=10 (pH 5.6) and 23 (pH 3.8). It is suggested that catalytically active monomeric and dimeric PAP forms are entrapped in reverse micelles of w0=10 and 23, respectively.

Acid Phosphatase↗
PubMed1982

Secretion into and elimination from blood circulation of prostate specific acid phosphatase, measured by radioimmunoassay.

The concentration of prostate specific acid phosphatase (PAP) was significantly higher in serum specimens from prostatic venous plexus blood than from peripheral venous blood in 6 patients operated upon because of benign prostatic hypertrophy. This suggests that normally circulating PAP is secreted via the prostatic venous plexus. We also investigated the disappearance of PAP from the circulation after total prostatectomy and staging pelvic lymphadenectomies in 5 patients with nonmetastazing prostatic cancer and in 1 patient with bladder cancer. During the postmaximum period, serum PAP concentrations declined, following 2-exponential curves, the 1st mean half life of elimination being 1.2 hours (range 0.5--2.5 hours). It is possible that PAP released from the prostate during the operation was eliminated during the 1st period. The 2nd half life was found to be remarkably long (mean = 281 hours), and it may represent PAP bound by serum protein(s).

Acid Phosphatase↗
PubMedDate not supplied

Partial purification and characterization of a non-specific acid phosphatase in leaves and root nodules of Phaseolus vulgaris.

Acid phosphatase (ACP) activity in common bean grown with or without 1.5 mM of phosphate has been examined. Leaves and root nodules responded to the absence of an exogenous phosphate source with an increase in ACP activity. Increases in enzyme activity were not associated with the synthesis of new isoforms of the enzyme. We partially purified and characterized the ACPs, which consisted of three proteins, one of leaf and two of nodule. Proteins of leaf migrated at 72 and 51 kDa in SDS-PAGE, whereas that of nodule migrated at 72, 49, 41 and 34 kDa. Enzymes of both organs had a pH optimum of 5.6, and were relatively heat stable. The enzymes exhibit a broad substrate selectivity, with maximal activity obtained with alpha-naphthyl-phosphate, ribulose 1,5-bisphosphate and p-nitrophenyl-phosphate (p-NPP). Potent inhibition by Zn2+, Hg2+, Cu2+, Pb2+, Al3+ and (MoO4)2- was observed.

Acid Phosphatase↗
PubMed1982

Acid phosphatases of dog testis and a Leydig cell tumor.

Acid phosphatase activities were measured with five different substrates after fractionation with Sepharose 6B and DE-52 cellulose chromatography of homogenate from normal adult dog testis and a testicular tumor. The tumor showed a positive 3 beta-hydroxysteroid dehydrogenase reaction and was diagnosed as a Leydig cell adenoma. The fractionations gave three separate enzyme activities in the normal testis and two enzymes in the tumor. All were sensitive to sodium fluoride, but differed from each other in pH-optima and the response to Co2+ and Zn2+. Enzymes I and II were identical in both tissues. The latter with a smaller molecular weight was activated by Zn2+ but not by Co2+ and had slightly higher pH-optimum (4.5) than enzyme I (optimum at pH 3.5). The third enzyme was activated by Co2+ and Zn2+ and had the highest pH-optimum (pH 5.5). It was called enzyme IV due to its resemblance to a similar activity in other mammalian species.

Acid Phosphatase↗
PubMed1983

Perspectives on serum acid phosphatase in prostatic disease. An evaluation of two methods.

Acid phosphatase in serum was measured in 116 patients with prostatic disease, benign in 59 and malignant in 57 cases. Comparisons were made between radioimmunoassay (RIA) and an enzymatic method. The correlation coefficient between the respective values was 0.96 in patients with untreated prostatic cancer, indicating that no significant difference between results with the two methods was to be expected. The correlation coefficient between RIA values and cancer stage was 0.48, and between catalytic activity and cancer stage it was 0.50. The validity of the two methods consequently was equal. RIA, however, was the more sensitive method, giving elevated values in 10 of 11 patients with untreated stage III or stage IV prostatic cancer, as compared with only 4 of the same 11 in the enzymatic assay. This seeming paradox most probably was attributable to differing intrinsic properties of the methods when the upper limits of normal range were established. Neither RIA nor enzymatic analysis discriminated early prostatic cancer (stages I and II) from benign lesions.

Acid Phosphatase↗
PubMed1981

Effect of colchicine on the Golgi apparatus and on GERL of rat jejunal absorptive cells. Ultrastructural localization of thiamine pyrophosphatase and acid phosphatase activity.

Ultrastructural localization of thiamine pyrophosphatase (TTP) and acid phosphatase (AcPase) activity was performed on jejunal absorptive cells of rats pretreated with the antimicrotubular agent colchicine and of control animals. Demonstration of TPP activity showed that most of the dislocated Golgi stacks after colchicine application lacked positively staining cisternae of the mature side. This cytochemical finding is in agreement with the morphologically demonstrable changes of the Golgi stacks resulting in a loss of polarity and give evidence for a colchicine-induced deficiency of the Golgi apparatus. The cytochemical localization of AcPase activity showed deposits of reaction product over lysosomes and GERL and demonstrated a dislocation of GERL occurring concomitantly with the changes of the Golgi apparatus. The antimicrotubular effect of colchicine is well documented; thus the morphological and cytochemical changes of the Golgi apparatus and of GERL might be due to a disturbed microtubular function after application of this agent suggesting an influence of microtubules in the maintenance of the integrity of these organelles. This hypothesis includes the possibility of an involvement of microtubules in formation and differentiation of Golgi stacks and GERL as well as a kind of "skeletal"function being responsible for their characteristic structure and fashion.

Acid Phosphatase↗
PubMed1979

Evaluation of histochemical observations of activity of acid hydrolases obtained with semipermeable membrane techniques. 3. The substrate specificity of isoenzymes of acid phosphatase in m.gastrocnemius of rabbits.

Three distinct isoenzymes of acid phosphatase have been separated from extracts of m.gastrocnemius of normal and of vitamin E deficient rabbits by gel filtration and polyacrylamide gel electrophoresis. These isoenzymes, termed I, II and III, have molecular weights of: 110,000--130,000, 60,000--78,000 and 12,500--14,500. Isoenzymes I and II split the substrates 4-methylumbelliferyl phosphate and naphthol AS-BI phosphate and the activity is strongly increased in the muscles of vitamin E deficient rabbits. Isoenzyme III splits only 4-methylumbelliferyl phosphate and the activity is not increased in the muscles of vitamin E deficient rabbits. The pH-optimum for isoenzymes I and II is 4.8 and for isoenzyme III 5.5. It has been shown that the histochemical semipermeable membrane technique, using substrate naphthol AS-BI phosphate, is a very reliable technique for demonstrating activity of the isoenzymes I and II in tissue sections. On the other hand, activity of isoenzyme III cannot be demonstrated with this histochemical technique. In pathologically altered muscles, the activity of the isoenzymes I and II is greatly increased whilst the activity of isoenzyme III is not significantly altered.

Acid Phosphatase↗
PubMed1984

Acid phosphatase in human breast cancer tissue.

When the total acid phosphatase (AP) activity of mammary carcinoma was compared with those of benign pathology and normal mammary tissue the results showed statistically significant differences (P less than 0.05) when expressed per milligram of protein: 358 +/- 42 nmoles per hour (mean +/- standard error) in the malignant tumor, 216 +/- 30 in the benign pathology, and 96 +/- 45 in normal tissue and when expressed per milligram of DNA: 1858 +/- 234, 1227 +/- 140, 695 +/- 345 nmoles per hour, respectively. The polyacrylamide gel electrophoretic profiles showed different levels of isoenzymes 3 and 4 in the three tissue groups. The appearance of isoenzyme 1 is reported after treatment of the homogenates with 5% Triton X-100. It was also found by counterimmunoelectrophoresis that the 28,000 Xg mammary tumor supernatant cross reacts with an antiserum raised against AP isoenzyme 2 although the mammary tissue does not contain such an isoenzyme. To elucidate this point, isoenzymes 1, 3 and 4 were separated by columns of Sephadex G-200 and DEAE-Sephadex. By counterimmunoelectrophoresis, it was observed that only the fraction containing isoenzyme 4 cross-reacted with the antiserum anti-AP isoenzyme 2 maintaining the catalytic activity.

Acid Phosphatase↗
PubMed1989

Function of the PHO regulatory genes for repressible acid phosphatase synthesis in Saccharomyces cerevisiae.

Expression of the repressible acid phosphatase (rAPase) gene, PHO5, of Saccharomyces cerevisiae is repressed by a certain level of inorganic phosphate (Pi) in the medium and is derepressed when the Pi concentration is lowered. The Pi signals are conveyed to PHO5 by a regulatory system consisting of proteins coded for by the PHO2, PHO4, PHO80 and PHO81 genes. We have found that the transcription of PHO81 is regulated by Pi through the PHO regulatory system. Increasing the dosage of PHO4 and PHO81 by ligating each gene to YEp13 gives rise to, respectively, considerable and weak synthesis of rAPase by cultivation of the transformants in high-Pi medium; but in low-Pi medium, increased dosage of PHO4 stimulates the rAPase synthesis significantly, whereas PHO81 has no effect. Increased dosage of PHO2 stimulates rAPase synthesis considerably in low-Pi but not in high-Pi. A coordinate increase of PHO80 cancels the dosage effect of PHO4, but not that of PHO81. Coordinate increases of PHO80 and PHO2 give rise to the same phenotype as an increased dosage of PHO80 alone. The level of the PHO4 protein was found to be the limiting factor of the rAPase synthesis and the copy number of the PHO5 gene not to be. These facts accord with the idea that the PHO80 protein transmits the Pi signals to the PHO5 gene via the PHO4 protein, whereas the PHO2 protein does not have a direct function in the signal transmission.

Acid Phosphatase↗
PubMed1991

Biphasic effect of calcitonin on tartrate-resistant acid phosphatase activity in isolated rat osteoclasts.

Tartrate-resistant acid phosphatase (TRAP) has been implicated as being involved in osteoclastic bone resorption, and calcitonin (CT) is known to inhibit the resorptive process. This study investigates the kinetics of CT action on TRAP activity in isolated rat osteoclasts using both biochemical and quantitative cytochemical methods. The latter technique has been developed to detect very small changes in intracellular TRAP activity at the single-cell level. The biochemical study showed that 10(-9) M salmon CT (sCT) decreased TRAP activity in medium throughout the experimental period; TRAP activity in the cells was increased during the first 2 h but subsequently declined and was decreased to a significant level at 6 h. TRAP activity in sCT-treated osteoclasts measured by the cytochemical method showed significant increases within the first hour. This response was dose dependent between 10(-16) and 10(-11) M sCT with EC50 at 8 X 10(-14) M. After 1 h, the initial increase in intracellular TRAP activity in CT-treated osteoclasts was followed by a decline to below control levels, reaching statistical significance at 9 h. Treatment with forskolin (10(-5) M) showed a similar trend, suggesting that this response is mediated by cyclic AMP-regulated phosphorylation events. From these results, we conclude that CT has two actions on TRAP in isolated rat osteoclasts: the first to inhibit its release, the second to inhibit its synthesis and/or increase its degradation.

Acid Phosphatase↗
PubMed1993

Regulation of the expression of prostatic acid phosphatase in LNCaP human prostate carcinoma cells.

Human prostatic acid phosphatase (PAcP) is a prostate epithelium-specific differentiation antigen and its expression has been proposed to be regulated by androgens. Since cellular PAcP may function as a protein tyrosine phosphatase, we investigated the regulatory mechanism of its expression at different growth stages in LNCaP cells, the only cultured human prostate carcinoma cells that express an endogenous PAcP. Cells were plated at different densities to represent different stages of cellular growth for quantitating the expression of PAcP. In 4-d subconfluent cells, the cellular PAcP activity and protein level increased following the seeded cell density, consistent with mRNA levels. By day 7, all cultures had an approximately equal amount of total cellular proteins, indicating that cell growth approached to confluence, except the one that was plated at the lowest density. The cellular PAcP activity per cell was increased and corresponded to its protein level as observed in 4-d cultures. However, in 7-d cultured cells, although the PAcP protein level increased, its mRNA level declined. This increased PAcP protein level despite the decreased message was in part due to a prolonged half-life of the protein. Further, androgen effect on the PAcP mRNA level was also shown to be a cell density-dependent phenomenon. In low-density cultured cells, the PAcP mRNA level was elevated approximately 100% by 5 alpha-dihydrotestosterone (DHT) stimulation. However, in high-density confluent cells the mRNA level was slightly decreased by DHT treatment. Further, treatments with various growth stimulators resulted in various degrees of inhibition on PAcP mRNA levels. In conclusion, the data indicate that the cellular level of PAcP activity is associated with the cell density/confluence of LNCaP cells. Further, cell density could modulate androgen effect on PAcP expression at the mRNA level.

Acid Phosphatase↗
PubMed1975

Bacterial antigen and acid phosphatase in macrophages in experimental pyelonephritis.

Experimental retrograde E. coli pyelonephritis was produced in rats. The study covered the period from 6-24 hours up to 6 months. Macrophages in the renal tissue were studied using immunofluorescence staining for bacterial E. coli antigen and histochemical staining for aicd phosphatase. A comparison of sections stained according to the two methods showed that antigen-containing macrophages in nearly all cases yielded a positive reaction for acid phosphatase. On the other hand, in several kidneys acid phosphatase-positive macrophages occurred which in consecutive sections studied by immunofluorescence did not contain antigen. The possibility of using staining for acid phosphatase as a screening method for the detection of active, antigen-containing macrophages in human chronic pyelonephritis is discussed.

Acid Phosphatase↗
PubMed2005

Direct observation of multiple protonation states in recombinant human purple acid phosphatase.

To date, most spectroscopic studies on mammalian purple acid phosphatases (PAPs) have been performed at a single pH, typically pH 5. The catalytic activity of these enzymes is, however, pH dependent, with optimal pH values of 5.5-6.2 (depending on the form). For example, the pH optimum of PAPs isolated as single polypeptides is around pH 5.5, which is substantially lower that of proteolytically cleaved PAPs (ca. pH 6.2). In addition, the catalytic activity of single polypeptide PAPs at their optimal pH values is four to fivefold lower than that of the proteolytically cleaved enzymes. In order to elucidate the chemical basis for the pH dependence of these enzymes, the spectroscopic properties of both the single polypeptide and proteolytically cleaved forms of recombinant human PAP (recHPAP) and their complexes with inhibitory anions have been examined over the pH range 4 to 8. The EPR spectra of both forms of recHPAP are pH dependent and show the presence of three species: an inactive low pH form (pH pK( a,2)). The pK( a,1) values observed by EPR for the single polypeptide and proteolytically cleaved forms are similar to those previously observed in kinetics studies. The spectroscopic properties of the enzyme-phosphate complex (which should mimic the enzyme-substrate complex), the enzyme-fluoride complex, and the enzyme-fluoride-phosphate complex (which should mimic the ternary enzyme-substrate-hydroxide complex) were also examined. EPR spectra show that phosphate binds to the diiron center of the proteolytically cleaved form of the enzyme, but not to that of the single polypeptide form. EPR spectra also show that fluoride binds only to the low pH form of the enzymes, in which it presumably replaces a coordinated water molecule. The binding of fluoride and phosphate to form a ternary complex appears to be cooperative.

Acid Phosphatase↗
PubMed1975

Nonspecific acid phosphatase from Schizosaccharomyces pombe. Purification and physical chemical properties.

Repressible nonspecific acid phosphatase from Schizosaccharomyces pombe was purified to apparent homogeneity, as ascertained from ultracentrifugal, electrophoretic, and chromatographic data. The native protein has a molecular weight of 383,000 as determined by sucrose density gradient centrifugation and 381,000 as determined by gel filtration. The native protein can be dissociated in the presence of 8 M urea-1% sodium dodecyl sulfate into sub-units possessing an approximate molecular weight of 104,000. Neutral sugars account for about 66% of the total molecular weight and contribute to the high solubility and some of the other physical properties of this enzyme. Purified enzyme preparations have a Km for 4-nitrophenyl phosphate of 0.17 mM and a broad substrate specificity, but do not show diesterase activity. Phosphate and sulfate are competitive inhibitors. The enzyme is inactivated at neutral and alkaline pH and at relatively low temperatures. Mannose and galactose was found as the main components of the carbohydrate moiety; glucosamine was present in lower amounts. The amino acid analysis revealed a high content of aspartate, threonine, and serine; no sulfhydryl group could be detected. Pi is released in stoichiometric amount (1 mol per enzyme monomer) on protein digestion.

Acid Phosphatase↗
PubMed2006

Stability and reactivity of acid phosphatase immobilized on composite beads of chitosan and ZrO2 powders.

Equal weights of chitosan and ZrO2 powders were mixed in acetic acid solution to prepare the composite beads. They were then cross-linked with glutaraldehyde and stored with and without freeze-drying before use. The physicochemical properties of acid phosphatase immobilized on four types of the supports (wet/dried pure chitosan beads, wet/dried chitosan-ZrO2 composite beads) were compared. Various parameters including glutaraldehyde concentration, cross-linking time, enzyme concentration, temperature, and pH on enzyme activity were studied. It was shown that the activity yield of enzyme immobilized on the dried chitosan-ZrO2 beads was the highest, and the relative activity remained above 83.2% within pH 2.9-5.8. Regardless of wet or dried beads, the Michaelis constant KM and maximum rate of reaction Vmax of acid phosphatase immobilized on chitosan-ZrO2 composite beads were 1.8 times larger than those on pure chitosan beads. Of the four immobilized enzymes, the use of wet chitosan-ZrO2 bead as the support showed the lowest thermal deactivation energy (78 kJ mol(-1)).

Acid Phosphatase↗
PubMed1980

A discrete multichannel procedure for the determination of acid phosphatase activities in serum.

The purpose of this study was to increase the capacity of the laboratory to perform analyses for the acid phosphatase activities by adapting the previous manual method to a discrete multichannel, computer controlled photometer. The modified system was far superior to the manual method, showing an improvement in the accuracy and precision of the method as well as a three times higher efficiency of the method for analyses. The reference values for serum acid phosphatase and its tartrate stable fraction were determined from apparently healthy women and men. The clinical significance of the method was discussed on the basis of the year's experience.

Acid Phosphatase↗