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PubMedDate not supplied

Acid phosphatases in the human testis after prolonged estrogen treatment.

The testes of 2 autopsied adult men and 6 subjects, suffering from prostatic carcinoma, were analysed for acid phosphatase activities, Two of the prostatic patients had been receiving estrogen treatment at least for a year and had completely regressed testes. Testes of other subjects contained well-defined tubules with different spermatogenic cells in abundance. The total acid phosphatase activity, assayed in the homogenate, showed a marked reduction in the testes of estrogen-treated subjects. Enzymes were separated by cellulose chromatography or by gel filtration combined with cellulose chromatography. Three activity peaks were resolved by the former and four by the latter technique, when homogenates of the control testes were used. In contrast, two to three strongly reduced activities could be discerned from the testes of estrogen-treated subjects. The specific activity of each enzyme after fractionation was compared between control and regressed testes. No difference was observed in the activities of enzyme I. Enzyme II was markedly reduced in the regressed testes, but was clearly present. Enzymes III and IV were either totally absent or showed a marked reduction in the regressed testes. It is suggested that a correlation exists between the destruction of germ cells, as a consequence of estrogen treatment, and the marked reduction in the activity of enzymes III and IV.

Acid Phosphatase↗
PubMed1993

In vitro binding of plasma membrane-coated vesicle adaptors to the cytoplasmic domain of lysosomal acid phosphatase.

Sorting of the newly synthesized membrane-bound precursor of lysosomal acid phosphatase (LAP) involves internalization from the plasma membrane via clathrin-coated pits. Using an in vitro system, we present direct evidence for high affinity interaction of the cytoplasmic domain of LAP with the amino-terminal trunk portion of plasma membrane-coated vesicle adaptors. Coated vesicle adaptors of the trans-Golgi network displayed poor binding to LAP, but high affinity binding to the cytoplasmic tail of the 46-kDa mannose 6-phosphate receptor, which is included in clathrin-coated pits of the trans-Golgi network. Binding of plasma membrane adaptors to the tail peptide of LAP required an internalization signal that contains either tyrosine or phenylalanine.

Acid Phosphatase↗
PubMed1980

Autosomal dominant aniridia: probable linkage to acid phosphatase-1 locus on chromosome 2.

Maximum likelihood analysis for linkage between autosomal dominant aniridia and 12 biochemical and serological markers in a single large family showed a probable linkage between autosomal dominant aniridia and the enzyme acid phosphatase-1. The presence of an autosomal dominant aniridia gene linked to acid phosphatase-1 on chromosome arm 2p and the existence of an aniridia syndrome resulting from deletion of band 13 of the short arm of chromosome 11 establishes a chromosome basis for genetic heterogeneity of aniridia phenotypes.

Acid Phosphatase↗
PubMed1991

Purple acid phosphatase from bovine spleen. Interactions at the active site in relation to the reaction mechanism.

Oxidation of the reduced (pink) phosphate-free bovine spleen acid phosphatase with 1.5 mol H2O2 or sodium peroxodisulfate/mol, in the presence of Mes or Bistris pH 5, leads to a species with an absorption maximum at 558 nm. Addition of acetate or oxidation in the presence of acetate buffer engenders a species with a maximum at 550 nm. Addition of phosphate to both species shifts the maximum immediately to 540 nm; this is the species also found after preparation from the spleen. The assumption that these species represent strongly bidentate-binding hydroxo, acetato and phosphato complexes of the Fe(III)-Fe(III) system is supported by replacement reactions with other ligating oxoanions followed by their typical spectral shifts. These oxoanion complexes cannot be dissociated by gel filtration; this is possible only after reduction to the Fe(II)-Fe(III) system. The oxidized species without EPR signals below g values of 2 still reveals 5% activity which cannot be reduced to zero even in the presence of higher concentrations of peroxodisulfate. The pH optimum of the reaction with alpha-naphthyl phosphate shifts from 5.9 to 5.3 in the oxidized species. The apparent pK values around 4.5 as derived from the pH dependence of activity, of the EPR spectra, and the spectral shifts of the phosphate-saturated reduced and oxidized species are assigned to an aquo/hydroxo equilibrium at the Fe(III) or an equilibrium, where the phosphato ligand is replaced by a hydroxo ligand. A reaction mechanism is proposed in which a hydroxo ligand at the chromophoric Fe(III) attacks the phosphoric acid ester group only when that is monoprotonated and pre-oriented by electrostatic interaction with the nonchromophoric metal ion. Binding and inhibition studies with the oxoanions indicate that they compete with the catalytically active hydroxo group of the reduced and oxidized enzyme with nearly the same inhibition constants. Catalysis is not affected by the oxoanions which replace the additional mu-hydroxo ligand in the 558-nm-absorbing Fe(III)-Fe(III) species. In contrast to hemerythrin and ribonucleotide reductase, a binuclear iron center is proposed for the purple acid phosphatase, which is bridged by a carboxylato and two aquo/hydroxo groups, but without a mu-oxo bridge.

Acid Phosphatase↗
PubMedDate not supplied

Loss of acid phosphatase from rat spermatozoa as a method for assessing the acrosome reaction.

A method is presented for evaluating the extent of the acrosome reaction by measuring the release of acrosomal acid phosphatase from rat spermatozoa during incubation under capacitating conditions. Treatment of spermatozoa with lysophosphatidylcholine or Triton X-100 released the acid phosphatase from the sperm cell. Using this enzymatic method we could not detect an alteration in enzyme activity following 5 h incubation under capacitating conditions. The effect of in vitro capacitation for 5 h in the absence or presence of heparin or ionophore A23187 was studied. Incubation in the presence of heparin (10 micrograms ml-1) caused a 32% increase in enzyme activity. After exposure of the spermatozoa to ionophore A23187 (0.5 microM) 16% increase of enzyme activity could be detected.

Acid Phosphatase↗
PubMed1984

Immunologically reactive tryptic fragments of human prostatic acid phosphatase.

Three peptide fragments (designated II, III and IV) of human prostatic acid phosphatase (PAP) were isolated to homogeneity from a limited tryptic hydrolysate of PAP by gel filtration on Sephadex G-100, followed by chromatography on DEAE-cellulose and Sephadex G-75. The homogeneity was confirmed by disc poly-acrylamide-gel electrophoresis. The Mr values were 32 500, 25 000 and 11 000 as estimated by gel filtration and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Immunoprecipitation study revealed that only fragment II formed an immune precipitate with anti-PAP antibodies. Fragment II exhibited 45% of maximum inhibitory activity on the reaction between PAP and goat anti-PAP IgG (immunoglobulin G) antibodies (or rabbit anti-PAP antibodies), whereas fragments III and IV demonstrated 24% (or 23%) and 29% (or 27%) inhibition respectively. A mixture of these three tryptic fragments of PAP result in 96% (for goat anti-PAP antibodies) and 94% (for rabbit anti-PAP antibodies) inhibitory activities, which were equivalent to the sum of maximum inhibitory activity of the three fragments individually. The results demonstrated that these three tryptic peptide fragments carried all the antigenic active sites of the native PAP, and suggested that the entire molecule of human PAP comprised a minimum of four distinguishable, nonoverlapping antigenic determinants. These three fragments also were shown to retain all the disulphide bonds of the native PAP, and thus were useful reagents for the elucidation of PAP molecular structure.

Acid Phosphatase↗
PubMed1967

Elution of loosely bound acid phosphatase from Staphylococcus aureus.

Strains of Staphylococcus aureus from the International-Blair and the Seto-Wilson series of phage propagating strains were examined for acid phosphatase activity. This enzyme was found to occur in varying amounts in three different fractions: free (6 to 60%), loosely bound (25 to 82%), and firmly bound (0 to 46%). Propagating strain 3A, because of its high activity, was chosen for further study. The rate of enzyme production paralleled cell growth in Trypticase Soy Broth, but followed a biphasic pattern in a semisynthetic casein acid-hydrolysate medium with glyceryl phosphate. Maximal elution of acid phosphatase in the loosely bound fraction, presumably from the surface of cells, occurred in the alkaline pH range. From log-phase cells, elution was maximally effected with buffered 1.0 M KCl (pH 7.5), but stationary-phase cells required twice the concentration of KCl.

Acid Phosphatase↗
PubMed1977

pH dependence and solvent isotope effects in the hydrolysis of phosphomonoesters by human prostatic acid phosphatase.

The pH dependence of the human prostatic acid phosphatase-catalyzed hydrolysis of p-nitrophenyl phosphate and beta-glyceryl phosphate has been studied over a wide range of pH and the values of Km and V calculated with the aid of the Cleland HYPER program. The pH dependence of Km shows the effect of substrate ionization: pK values of 5.6 and 6.4 are observed as for the respective values of free substrates. The pH dependence of both Km and V for each substrate reveals the involvement of an ionizable group in the ES complex which is ascribed to a phosphohistidine-enzyme intermediate. The small deuterium solvent isotope effects which are observed on V are consistent with values observed for solvolysis of phosphoramidates. The measured data for Km indicates limits on burst-titration experiments of prostatic acid phosphatase (orthophosphoric-monoester phosphohydrolase, EC 3.1.3.2).

4-Nitrophenylphosphatase↗
PubMed1984

Position effect variegation of an acid phosphatase gene in Drosophila melanogaster.

X-ray mutagenesis has produced a series of deficiencies in a duplication of part of the third chromosome containing the acid phosphatase gene (Acph-1) in Drosophila melanogaster. In one of these deficiencies, Acph-1 is shown to be undergoing position effect variegation. Naturally occurring electrophoretic variants of the enzyme were used to visualize and determine quantitatively the extent of variegation of the allele which is cis to the heterochromatic breakpoint. Alteration of genotypic background and temperature provided further evidence for position effect. Rocket immunoelectrophoresis was used to correlate the levels of acid phosphatase activity and protein in flies containing the deficiency. A novel result indicates that the variegation is not the consequence of an averaging of active and inactive cells, but rather due to a quantitative alteration of gene activity within at least some individual cells.

Acid Phosphatase↗
PubMed1991

[Biological profile and value of determination of tartrate-resistant acid phosphatase in children].

The serum level of tartrate-resistant acid phosphatase (TRAP) was measured in 130 children (61 M: 69 F). TRAP was found to be significantly higher in children under 5 years (n = 20) than in those aged between 5 and 9 years (n = 47) (8.3 + 2.4 vs 6.3 + 1.3 U/L, p less than 0.05). This last group had significantly lower TRAP levels than the one composed by children between 10 to 14 years (n = 60) (6.3 + 1.3 vs 7.5 + 1.2 U/L, p less than 0.02). We observed that a significant correlation existed between TRAP and alkiline phosphatase (r = 0.672, p less than 0.001). There was no correlation between TRAP and age and no difference between sexes. These results suggest that TRAP is useful as a marker of bone remolding in children.

Acid Phosphatase↗
PubMed1996

Tartrate-resistant acid phosphatase from human bone: purification and development of an immunoassay.

Tartrate-resistant acid phosphatase (TRAP) was purified 20,000-fold to apparent homogeneity from human bone. The purified enzyme consisted of one 32 kd subunit, which was cleaved by beta-mercaptoethanol into two subunits of 15 kd and 20 kd, as shown by sodium dodecyl sulfide-polyacrylamide gel electrophoresis (SDS-PAGE) and silver staining. The purified enzyme was identified by N-terminal amino acid sequencing, and it was shown to be homologous with previously purified TRAPs from other sources. We developed a polyclonal antiserum against the purified enzyme in mice. In immunohistochemistry, the antiserum recognized osteoclasts from human bone and alveolar macrophages from human lung tissue, but no cells from human spleen tissue. It also stained osteoclasts from rat bone cells cultured on bovine bone slices. Purified TRAP could be inhibited by vanadate and molybdate, but not by tartrate, and it was activated 2-fold by beta-mercaptoethanol. The glycoprotein structure of human bone TRAP was analyzed, and it was shown to contain only high-mannose type carbohydrates. We used the polyclonal antibody to develop a competitive fluorescence immunoassay for measuring serum TRAP concentrations. According to the assay, children have higher serum TRAP concentrations than adults, and postmenopausal women have higher concentrations than premenopausal women. Postmenopausal women also have higher serum TRAP concentrations than postmenopausal women on estrogen replacement therapy.

Acid Phosphatase↗
PubMed1987

Importance of acid phosphatase in response criteria for prostate cancer.

The role of acid phosphatase in the definition of response to treatment for prostate cancer is unclear. To better define its predictive value, especially regarding survival rate, we reviewed the clinical course of 76 men with Stage D2 prostate cancer who were treated with combination chemotherapy.

Acid Phosphatase↗
PubMed1976

Regulation of phosphate metabolism in Neurospora crassa: identification of the structural gene for repressible acid phosphatase.

A mutant of Neurospora crassa with an altered repressible acid phosphatase has been isolated. The enzyme is much more thermolabile than that of wild type, and has an increased Michaelis constant. Tests of allelic interactions (in partial diploids) and in vitro mixing experiments were consistent with the mutation being in the structural gene for the enzyme. This gene, pho-3, was found to be located in the right arm of Linkage Group IV (LGIV). Thus, pho-3 and the structural gene for repressible alkaline phosphatase, pho-2 (LG V), map in separate linkage groups and cannot be part of the same operon. Neither of these structural genes is linked to the known regulatory genes, nuc-1 (LG I), nuc-2 (LG II), and preg (LG II).

Acid Phosphatase↗
PubMed1998

Persistently raised serum acid phosphatase activity in a patient with hypophosphatasia: electrophoretic and molecular weight characterisation as type 5.

Hypophosphatasia is a rare disorder characterised by low levels of serum alkaline phosphatase activity resulting in abnormal phosphorylated metabolites and varying skeletal abnormality. We have followed a patient with adult type hypophosphatasia for over ten years who has also shown a persistently elevated tartrate resistant acid phosphatase activity (TRAP) without any obvious cause. Characterisation of this TRAP by polyacrylamide gel electrophoresis (pH 4.0) showed migration to band 5 position. Molecular weight determination by FPLC and an estimate of the molecular weight by gradient gel electrophoresis gave a molecular weight of 29,000-43,600. This molecular weight makes it unlikely for this to be a IgG/TRAP complex persisting in the circulation. Paranitrophenylphosphate was the preferred substrate. This characterises the enzyme as type 5 acid phosphatase which is of the mononuclear/phagocyte type, possibility of osteoclastic origin, though the tissue source remains unknown.

Acid Phosphatase↗
PubMed1983

Localization of acid phosphatase activity in testosterone-treated prostatic urethra of human fetuses.

Androgens accelerated differentiation of human fetal urethral epithelial cells into secretory prostatic cells in organ culture. These epithelial cells contained supranuclear Golgi complexes in which acid phosphatase enzyme activity could be demonstrated by an electron microscopic histochemical technique. Most of the acid phosphatase activity was localized in lysosomes. Some apical precipitates could also be seen. This apical activity might be in secretory granules. Also, mesenchymal cells contained this enzyme.

Acid Phosphatase↗