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At least 973 records · Page 54Linked to original sources
PubMed1994

Effect of cell density on androgen regulation of the mRNA level of human prostatic acid phosphatase.

The expression of human prostatic acid phosphatase (PAcP), a differentiation antigen of prostate epithelial cells, has been proposed to be regulated by androgen. We investigated this regulatory mechanism at the post-transcriptional level in LNCaP human prostate carcinoma cells, the only cultured cells that express PAcP. Our results demonstrated that the level of PAcP mRNA decreased when the cell density increased. Further, 5 alpha-dihydrotestosterone, an active form of the endogenous androgen, stimulated the PAcP mRNA level in low-density cells; while, caused a decrease in high-density cells. Thus, in LNCaP human prostate carcinoma cells, cell density could modulate PAcP expression at the mRNA level including androgen regulation.

Acid Phosphatase↗
PubMed1996

Superactivity and phase-sensitivity of potato acid phosphatase entrapped in reverse micelles.

Potato acid phosphatase, AcPase (E.C. 3.1.3.2) was entrapped in reverse micelles of cationic surfactant cetyltrimethylammonium bromide (CTAB) in isooctane and chloroform (1:1). The activity was studied at different values of Wo = ([water]/[surfactant]). AcPase exhibited superactivity in the reverse micellar system. At very low Wo value, activity was found to be less than that of in buffer and further increase in Wo value enhanced the activity thousand fold. At Wo = 50, the activity was enhanced more than twenty fold. The effect of second surfactant, TritonX-100, on superactivity was studied. There was a slight decrease in overall activity, when 3.33 mM TritonX-100 was added to the above reverse micellar system.

Acid Phosphatase↗
PubMed2002

Enhancement of nucleoside phosphorylation activity in an acid phosphatase.

Escherichia blattae non-specific acid phosphatase (EB-NSAP) possesses a pyrophosphate-nucleoside phosphotransferase activity, which is C-5'-position selective. Current mutational and structural data were used to generate a mutant EB-NSAP for a potential industrial application as an effective and economical protein catalyst in synthesizing nucleotides from nucleosides. First, Gly74 and Ile153 were replaced by Asp and Thr, respectively, since the corresponding replacements in the homologous enzyme from Morganella morganii reduced the K(m) value for inosine and thus increased the productivity of 5'-IMP. We determined the crystal structure of G74D/I153T, which has a reduced K(m) value for inosine, as expected. The tertiary structure of G74D/I153T was virtually identical to that of the wild-type. In addition, neither of the introduced side chains of Asp74 and Thr153 is directly involved in the interaction with inosine in a hypothetical binding mode of inosine to EB-NSAP, although both residues are situated near a potential inosine-binding site. These findings suggested that a slight structural change caused by an amino acid replacement around the potential inosine-binding site could significantly reduce the K(m) value. Prompted by this hypothesis, we designed several mutations and introduced them to G74D/I153T, to decrease the K(m) value further. This strategy produced a S72F/G74D/I153T mutant with a 5.4-fold lower K(m) value and a 2.7-fold higher V(max) value as compared to the wild-type EB-NSAP.

Acid Phosphatase↗
PubMed1985

Plasma cell acid phosphatase score in multiple myeloma and related disorders.

A detailed classification of plasma cells stained for acid phosphatase activity is introduced. With this method, patients with multiple myeloma, non-myeloma gammopathies, reactive plasmacytosis and other diseases in which plasma cells are involved, were investigated. The results show that our method can discriminate between multiple myeloma and reactive plasmacytosis. The overlap between multiple myeloma and other monoclonal gammopathies is much smaller than observed in other studies. Surprisingly low levels of acid phosphatase activity were found in the cells from patients with lymphoplasmacytoid immunocytoma. It is concluded that the acid phosphatase score can be of value for studying disorders in which plasma cells are involved.

Acid Phosphatase↗
PubMed1979

Does rectal examination affect serum acid phosphatase levels?

Formol-stable serum acid phosphatase (SAP) was measured in 200 patients with symptoms of prostatism, before and at varying time intervals after digital rectal examination. In three separate groups of 50 patients SAP levels were measured before and at 5, 15 and 30 min following rectal examination and in a fourth group of 50 patients it was measured before and at 6, 24 and 48 h after examination. No significant change occurred in SAP levels following this examination in any of the groups studied. We conclude that rectal examination does not raise the SAP and that, contrary to popular belief, blood levels recorded at any time within this 48-h period are reliable.

Acid Phosphatase↗
PubMed1981

The evaluation of a new enzyme immunoassay for the measurement of prostatic acid phosphatase.

An enzyme immunoassay for prostatic acid phosphatase (PAP) has been assessed. An upper limit normal is set at 1.8 microgram/1. There is a very low incidence of raised levels in chronic diseases or cancers other than those of the prostate. Patients with well-controlled prostatic cancer have levels less than 1.8 microgram/1 and show little variation about their own mean. PAP can rise exponentially with a doubling time of 1-5 months. This assay is unlikely to increase the detection of asymptomatic prostatic cancer as 66% of T0-2NXM0 cases had PAP less than 1.8 microgram/1. The main advantages over routine enzyme assays are its sensitivity and accuracy in the lower range.

Acid Phosphatase↗
PubMedDate not supplied

Behaviour of leukocyte acid phosphatase in various chronic diseases.

Leukocyte acid phosphatases were investigated in 146 patients with different chronic diseases. The method of investigation used was that of Kaplow and Burstone slightly modified by the authors in what regards the pH of the incubation medium. Normal or slightly increased scores were observed in the granulocytic series of patients with chronic myeloid leukemia. In patients with rheumatoid arthritis, chronic hepatitis, lupus erythematosus disseminatus and chronic lymphocytic leukemia a moderate enzymatic activity was generally observed in the lymphocyte and more marked in severe forms of disease. A marked increase of the enzyme activity was observed in patients with myeloma. The possibility of a correlation between the intensity of enzyme activity and immunoglobulin formation is discussed.

Acid Phosphatase↗
PubMedDate not supplied

Behaviour of leukocyte acid phosphatase in various chronic diseases.

Leukocyte acid phosphatases were investigated in 146 patients with different chronic diseases. The method of investigation used was that of Kaplow and Burstone slightly modified by the authors in what regards the pH of the incubation medium. Normal or slightly increased scores were observed in the granulocytic series of patients with chronic myeloid leukemia. In patients with rheumatoid arthritis, chronic hepatitis, lupus erythematosus disseminatus and chronic lymphocytic leukemia a moderate enzymatic activity was generally observed in the lymphocyte and more marked in severe forms of disease. A marked increase of the enzyme activity was observed in patients with myeloma. The possibility of a correlation between the intensity of enzyme activity and immunoglobulin formation is discussed.

Acid Phosphatase↗
PubMed1982

Ultrastructural localization of acid phosphatase activity in the large intestinal principal cells of postnatal rats.

A study was made of ultrastructural localization of acid phosphatase activity in the large intestinal mucosa of postnatal and adult rats. In rats 1 to 5 days old, phosphatase activity was observed on the microvillous membrane, the lateral cell membrane, the Golgi apparatus, the GERL of Novikoff (1963), the tubulo-vacuolar system, and on the supranuclear vacuole of the principal cells of the cecum and the ascending colon. In 30-day-old adult rats acid phosphatase activity, was noted on the GERL and the lysosomes of the principal cells in the cecum and the ascending colon. In all rats, young and adult, acid phosphatase activity was found only on the lysosomes and the GERL of the principal cells of the descending colon. Therefore, it was concluded that the acid phosphatase-containing tubulo-vacuolar system and the supranuclear vacuole in the surface principal cells of the proximal part of the large intestine of suckling rats may possess a strong phagolysosomal function as well as having an absorption capacity the same as ileal cells of suckling rats (Ono and Satoh 1981).

Acid Phosphatase↗
PubMed1992

Crystallization and preliminary crystallographic data of purple acid phosphatase from red kidney bean.

Purple acid phosphatase from red kidney bean has been crystallized from ammonium sulfate solutions in the pH range from 3.5 to 5.5. The crystal form is tetragonal bipyramidal and the largest crystals grew up to 2.0 mm long. Systematic absences indicate one of the enantiomorphic space groups P4(1)2(1)2 (92) or P4(3)2(1)2 (96) with cell dimensions a = b = 104.1(1) A and c = 308.7(2) A. The asymmetric unit contains one dimer with Mr of 110,700, determined by ultraviolet-laser desorption mass spectrometry. The crystals, with a salt-free density of 1.12 g/cm3 and a water content of 67%, diffract to 3.5 A.

Acid Phosphatase↗
PubMed1986

[Acid phosphatase distribution in the liver in cirrhosis].

The distribution of acid phosphatase in liver cirrhosis, as well as in its reverse development, was investigated in mice using histochemistry and electron histochemistry methods. Histochemistry demonstrated a sharp activity increase of acid phosphatase (as compared with the same in the material of partial hepatectomy) in liver cells (especially hepatocytes) during liver cirrhosis regression 10 days after a partial hepatectomy. Electron histochemistry has shown the enzyme withdraw out of hepatocytes and connective tissue cells of fibrotic stratum in the extra-cell medium. The reaction product localized on the neighbouring collagen fibres giving evidence that during reverse development of liver cirrhosis the lisosomal enzyme release from specified cells by means of exocytosis and they are involved in the lysis of collagen.

Acid Phosphatase↗
PubMedDate not supplied

[Effect of aluminium and cAMP on acid phosphatase from the apoplast of barley and maize root cells].

Acid phosphatase activity inhibited by 1 mM sodium molybdate was detected at the surface of barley seedling roots and in the cell wall fraction isolated from barley and maize seedling roots. This enzyme hydrolyzed NPP, GP, and PPi at low pH (4.0 and below). NPP hydrolysis was stimulated by magnesium (but not calcium or manganese) ions, while PPi hydrolysis was independent of the presence of bivalent ions. The activity of phosphatase localized in the cell walls of the both crops increased in the presence of 100 microM AlCl3 or CuCl2. Stimulation of NPP hydrolysis by micromolar concentrations of aluminium and copper as well as by millimolar concentrations of magnesium decreased in the presence of 25 microM cAMP. This agrees with the previous data on the enzyme localized at the outer side of the properly oriented vesicles in the microscomal fraction of plasmalemma. The role of the root extracellular acid phosphatase loosely associated with various apoplast structures in plant adaptation to toxic effect of aluminium in the acidic soils as well as possible control of this process by cAMP secretion to the apoplast are discussed.

Acid Phosphatase↗
PubMedDate not supplied

[Study of acid phosphatase II from Pichia guilliermondii yeasts].

Acid phosphatase II (AP II) was isolated from the cell-free extract of Pichia guilliermondii Wickerham ATCC 9058 and partially purified. The enzyme is a non-specific phosphomonoesterase. It hydrolyzes p-nitrohenyl-phophate (NPP), beta-glycerophosphate, glucose-6-phosphate, guanosine-5'-monophosphate, adenosine-5'-monophosphate, cytidine-5'-monophosphate, uridine-5'-monophosphate, alpha-naphtylphosphate, FMN. The order of the substrates corresponds to the degree of their hydrolysis decrease. The Michaelis constant of the enzyme was 1.4-10-3 M for NPP as a substrate, pH optimum was 5.5 and temperature optimum-40C. AP II was strongly inhibited by MoO4-2, F-, inorganic phosphate, Cu2+ and Be2+. The activity of the enzyme in the yeast cells does not change noticeably during growth on media with low and high iron content.

Acid Phosphatase↗
PubMed1984

[Prostatic acid phosphatase by enzymeimmunoassay].

We measured prostatic acid phosphatase levels by enzymeimmunoassay (PAP-EIA). Intraassay reproducibility of PAP-EIA was markedly good. In thirty normal males, PAP-EIA levels ranged from 0.24 ng/ml to 3.3 ng/ml, mean and S.D. being 0.94 ng/ml, 0.50 ng/ml, respectively. We made the upper limit of PAP-EIA for the normal range, 1.94 ng/ml (Mean + 2 S.D.). O 40 patients with untreated prostatic cancer, 34 patients (85%) gave positive results (1/3 33% of stage A, 3/4 75% B, 10/11 90% C, 20/22 90% D). One out of 12 patients with BPH, and one out of 11 with prostatitis gave positive results. The false positive rate was 9%. PAP levels of 324 samples from 111 patients with prostatic cancer were measured by EIA and radioimmunoassay (RIA). A significant correlation was noted between EIA and RIA (r = 0.997 p less than 0.001).

Acid Phosphatase↗
PubMed1982

Evidence for a spin-coupled binuclear iron unit at the active site of the purple acid phosphatase from beef spleen.

The purple acid phosphatase from beef spleen, which contains two iron atoms per molecule, is EPR silent in its native (oxidized) purple form. Treatment with mild reducing agents results in conversion to a pink, enzymatically active form, which exhibits an unusual EPR signal centered at g approximately equal to 1.77; double integration of the EPR spectrum gives one spin per two iron atoms. A similar EPR spectrum is observed for enzyme reduced anaerobically by one electron, using sodium dithionite. Variable-temperature magnetic susceptibility measurements show that the oxidized and reduced proteins are both antiferromagnetically coupled systems, with S = 0 and 1/2 ground states, respectively. Replacement of one of the iron atoms by zinc produces an FeZn enzyme with full catalytic activity. The FeZn enzyme exhibits a highly temperature dependent g = 4.3 EPR signal, and magnetic susceptibility data are consistent with an S = 5/2 paramagnet. Treatment of the FeZn enzyme with phosphate, a competitive inhibitor, results in sharpening of the EPR spectrum; double integration at 77 K gives one spin per iron. These results strongly suggest the presence of a spin-coupled bimetallic unit at the active site of the enzyme.

Acid Phosphatase↗
PubMed1989

Immunocytochemical localization of acid phosphatase in rat liver.

Localization of acid phosphatase (ACPase) in rat liver was investigated by immunocytochemical techniques. Rat liver was fixed by perfusion and cut into thick tissue slices, which were embedded in Epon or Lowicryl K4M. For light microscopy (LM), semithin Epon sections were stained for the enzyme ACPase by an indirect immunoenzyme technique. For electron microscopy (EM), ultra-thin Lowicryl K4M sections were stained by a protein A-gold technique. By means of LM, granular reaction deposits were observed in hepatocytes and sinus-lining cells. Stained granules were present in the juxtanuclear cytoplasm, but they did not correspond to a typical staining pattern for the Golgi complex. EM revealed that gold particles indicating ACPase antigens were present on lysosomes and on some vesicles locating in the trans Golgi region. Endosomelike vesicles were strongly positive for the labeling. Golgi cisterna were mostly negative, but weak signals were noted in dilated sacules. The plasma membranes on the sinusoidal and bile canalicular sides were labeled by a few gold particles. The results indicate that ACPase is present in endosomes and in a restricted area of plasma membrane, as well as in the lysosomal system.

Acid Phosphatase↗
PubMed1980

The determination of acid phosphatase of prostatic origin with the Automatic Clinical Analyzer (ACA, DuPont).

A critical evaluation of the determination of acid phosphatase of prostatic origin with the Du Pont ACA is reported. Th affinity of the enzyme towards certain substrates, and the specificity of sodium thymolphthalein monophosphate as a substrate for prostatic acid phosphatase were investigated. The validity of this method, which is supposed to be specific for prostatic phosphatase is, however, limited; clinical data showed that related human acid phosphatase interfere and decrease the specificity of the determination.

Acid Phosphatase↗