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At least 739 records · Page 41Linked to original sources
PubMed1977

Concomitance of basophilia, ribonucleic acid and acid phosphatase activity in regenerating muscle fibres.

Regenerating fibres from tibialis anterior muscles of mice and hamsters transplanted as minced fragments for 7 and 9 days respectively were compared for basophilia, ribonucleic acid (RNA) and acid phosphatase activity with fibres in muscles of patients with Duchenne muscular dystrophy, limb--girdle dystrophy and dermatomyositis. Normal muscles of mice, hamsters and humans were used as controls. In normal muscle fibres basophilia and RNA activity were restricted to the nuclei and acid phosphatase activity was occasionally observed in the nuclei, endomysial connective tissue and around muscle spindles. Diseased human muscle fibres were rich in acid phosphatase activity, the enzyme being most prominent in degenerating and basophilic fibres. When examined in serial sections, all basophilic fibres showed RNA and acid phosphatase activity. Similarly, all regenerating fibres in minced transplants which were basophilic to haematoxylin contained high RNA and acid phosphatase activity. It is suggested that basophilia in diseased human muscle fibres represents regeneration and that the lysosomes, as defined by acid phosphatase activity in these fibres, may be promoting their growth and differentiation by facilitating greater nucleocytoplasmic communication which ultimately could lead to protein synthesis.

Acid Phosphatase↗
PubMed1992

Human bone cells contain a fluoride sensitive acid phosphatase: evidence that this enzyme functions at neutral pH as a phosphotyrosyl protein phosphatase.

Fluoride is a potent therapeutic agent that increases spinal bone density in osteoporotic subjects. Based on work with animal cells previously, we proposed fluoride acts by inhibiting phosphotyrosyl protein phosphatase (EC 3.1.3.48) activity in bone cells. The presence of fluoride sensitive acid phosphatase (EC 3.1.3.2) activity was characterized in extracts of cultured human bone cells. Crude extracts contained acid phosphatase activity that was inhibited by fluoride with an apparent Ki of 12 mumol/L. The activity was investigated further by separating the acid phosphatase isoenzymes using CM Sepharose chromatography and a gradient of acetate pH 4.8-6.5. The major peak of activity recovered from CM Sepharose chromatography was characterized for stability, Km and inhibition by fluoride. The enzyme was sensitive to inhibition by tartrate, had a high affinity for paranitrophenylphosphate (apparent Km = 0.158 mupmol/L) and an apparent pH optimum of 4.8. Fluoride was a strong competitive inhibitor with an apparent Ki of 12.4 mumol/L. The column fractions containing the acid phosphatase were tested further for phosphotyrosyl protein phosphatase activity using [32P]labeled phosphotyrosyl histone as the substrate. Release of [32P]phosphate from this substrate at pH 7.0 was proportional to enzyme concentration and incubation time, demonstrating the presence of phosphotyrosyl protein phosphatase activity. The phosphotyrosyl protein phosphatase activity was inhibited by fluoride and had a pH optimum of approximately 7. These observations indicate that human osteoblasts contain a fluoride-sensitive phosphotyrosyl protein phosphatase. Thus, these results are consistent with the hypothesis that fluoride stimulates human bone cell proliferation by inhibiting the action of phosphotyrosyl protein phosphatase, thereby increasing the level of phosphorylated tyrosine residues which are known to play a role in increasing cell proliferation.

Acid Phosphatase↗
PubMed1985

Isolation and characterization of a homogeneous acid phosphatase from catfish liver.

A homogeneous, tartrate-inhibitable acid phosphatase (AcPase) was obtained from the liver of channel catfish (Ictalurus punctatus) by the use of Affi Gel-10-coupled aminohexyltartramic acid affinity chromatography. The enzyme has a molecular weight of 82,500 and is a dimer consisting of two apparently equivalent subunits with subunit weights of 35,000 +/- 3000. Amino acid composition data are presented and compared with those of mammalian acid phosphatases. Data suggest that the enzyme is a metalloacid phosphatase. Catfish liver AcPase exhibits two molecular forms with pI 5.66 and 5.37 which were separated by chromatofocusing. A spontaneous conversion of the less acidic form to a more acidic form was observed and this conversion was accompanied by a decreased sensitivity towards tartrate inhibition.

Acid Phosphatase↗
PubMed1989

Correlation of prostate-specific acid phosphatase and prostate-specific antigen immunocytochemistry with survival in prostate carcinoma.

Prostate-specific acid phosphatase, a secretory product of prostatic cells, may be a secondary product of the interaction of hormones with their receptor proteins. In this study we have examined two independent patient populations to see whether the intensity or extent of prostate-specific acid phosphatase and/or prostate-specific antigen staining correlated with survival and hormonal manipulation. One population of 24 patients was selected from patients undergoing surgical resection for adenocarcinoma Stage B or C at the Mayo Clinic. The second population of 123 patients was obtained from Radiation Therapy Oncology Group Protocols 75-06 and 77-06. Tissue from both populations was analyzed. In both populations, the intensity of prostate-specific acid phosphatase staining correlated with survival in a statistically significant manner. Staining with prostate-specific antigen was present in greater than 90% of specimens; data was therefore not analyzed. In those patients who subsequently relapsed and were subjected to hormonal manipulation, there appeared to be a higher likelihood of response to hormones with intense prostate-specific acid phosphatase staining.

Acid Phosphatase↗
PubMed1998

Melanosomes of retinal pigment epithelium--distribution, shape, and acid phosphatase activity.

The distribution and shape of melanosomes of the retinal pigment epithelium (RPE), and acid phosphatase activity in melanosomes were studied in rabbits. The rabbit eyes were observed using electron microscopy and enzyme cytochemical electron microscopy. The majority of melanosomes were located near the apical region of the RPE. Melanosomes in the RPE were classified as two shapes, elliptical and spherical or oval. Elliptical melanosomes were located parallel to the apical process and spherical or oval melanosomes were arranged vertically or obliquely to the apical process. We think that the distribution and shape of melanosomes contributes to the effective absorption and blocking of light coming from all directions. Almost all of the mature and immature melanosomes we identified showed positive in acid phosphatase reaction, indicating that melanosomes are commonly incorporated into the lysosomal system of the RPE. However, a few melanosomes showed negative in acid phosphatase reaction, suggesting that some melanosomes are stable and inert. The observed premelanosome showed negative reaction. Two types of melanosome-related complex granules were identified; melanosomes with a cortex of enzyme-reactive material (melanolysosome) and melanosomes with a cortex of lipofuscin (melanolipofuscin). These findings indicate tha a relationship between melanosomes and the lysosomal system of the RPE exists, and suggest that melanosomes may undergo modification or degradation in the cytoplasm. Also, the observation of a premelanosome and the positive acid phosphatase activity in mature and immature melanosomes indicates that melanosomes of the RPE may continue to be synthesized at a low rate in adult eyes.

Acid Phosphatase↗
PubMed1986

Acid phosphatase activity of cerebrospinal fluid cells in bacterial and abacterial meningitis.

Acid phosphatase staining is performed on cerebrospinal fluid cells of 365 samples from 105 patients with various types of meningitis. This enzyme activity is strongly positive in the early samples of bacterial meningitis, as far as the patients had not received a pretreatment with antibiotics for more than 24 h. It allows monitoring the response to therapy in subsequent samples. Acid phosphatase activity is positive in 2 cases of cryptococcus meningitis. It is negative in all cases of aseptic and Mycoplasma pneumoniae meningitis. The results in herpes encephalitis are variable, depending on the clinical state and the degree of brain destruction. Acid phosphatase staining is a useful and rapid cytological technique for determination of the nature of the meningitis and for monitoring the therapeutical response.

Acid Phosphatase↗
PubMed1995

Leishmania donovani: enhanced expression of soluble acid phosphatase in the presence of sinefungin, an antiparasitic agent.

Sinefungin, an antileishmanial nucleoside, induces morphological and ultrastructural changes in promastigotes of Leishmania donovani. The most important modifications are the enlargement of the flagellar pocket and the increased activity of the Golgi apparatus. Cytoenzymatic labeling demonstrates an increased activity of the soluble acid phosphatase in the flagellar reservoir of sinefungin-treated cells. The affinity constant remained unchanged. Analyzes by Western blot demonstrate an increased amount of the enzyme in the treated cells. The increased amount was not due to impaired enzyme release, as in the external medium the acid phosphatase was also enhanced but to a lesser extent. Under identical conditions the membrane-bound acid phosphatase was not modified. These results indicate that the enlargement of the flagellar pocket is the consequence of the accumulation of acid phosphatase and other Golgi-mediated enzyme provoking unbalanced cytoplasmic exchange. Sinefungin has the same effects on Leishmania tropica promastigotes. However, these effects are not specific to sinefungin. Another molecule, taxol, also induced cell rounding accompanied by increased acid phosphatase activity. Under conditions where cell rounding is not observed, in stationary phase or with compounds which stopped proliferation without shape change, no increase in the amount of acid phosphatase could be observed. These results clearly demonstrate a correlation between morphological, ultrastructural changes and the stimulated expression of acid phosphatase.

Acid Phosphatase↗
PubMed1985

Tartrate-resistant acid phosphatase in human alveolar macrophages.

Tartrate-resistant acid phosphatase has been extracted from human alveolar macrophages, in which its specific activity is 10-fold that in whole lung. The apparent identity of the alveolar macrophage isoenzyme with that associated with osteoclasts suggests that both types of cell belong to the mononuclear phagocyte system. Within this system, expression of tartrate-resistant acid phosphatase appears to accompany certain kinds of differentiation.

Acid Phosphatase↗
PubMed1983

[Acid phosphatase in blood (substrate: alpha-naphthylphosphate): reference values and diagnostic significance].

We report the results obtained with a modification of Hillmann's method (1) for determination of the catalytic concentration of acid phosphatase in serum using alpha-naphthylphosphate as the substrate. In a group of 158 males aged 16-85 years, the upper limit of the reference range (95th percentile) for the total acid phosphatase was established as 4.7 U/l (37 degrees C) and 4.2 U/l (30 degrees C), respectively; the corresponding values for the tartrate-inhibited acid phosphatase were 1.6 U/l (37 degrees C) and 1.5 U/l (30 degrees C). The upper limit of the reference range (95th percentile) for the total acid phosphatase determined in 60 females aged 18-80 years was 3.7 U/l (37 degrees C) and 3.0 U/l (30 degrees C). The catalytic concentrations in men and women did not show any age-related differences. The catalytic concentration of the tartrate-inhibited acid phosphatase was determined with the substrates alpha-naphthylphosphate and p-nitrophenylphosphate in a group of 89 patients with prostatic carcinoma (stages C and D). In 74 of these patients, the concentration of the prostatic specific acid phosphatase was assayed by enzyme-immunoassay and radioimmunoassay. The sensitivity of the method with p-nitrophenylphosphate was found to be unsatisfactory (66%), while that obtained with the other methods was superior and intercomparable (approx. 90%). The results obtained with the two substrates (p-nitrophenylphosphate vs. alpha-naphthylphosphate) differed significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗
PubMed1976

Ultrastructural histochemical localization of acid phosphatase in salivary glands of Drosophila melanogaster.

The ultrastructural histochemical localization of acid phosphatase in salivary glands of third instar larvae of Drosophila melanogaster has been studied. Using Gomori's lead phosphate method for acid phosphatase detection, the optimal incubation time in the reaction medium was determined to be 30 min. When glands having wild-type acid phosphatase activity are incubated for this time, deposition of the final reaction product is observed in essentially every lysosome and artifactual staining is minimal.

Acid Phosphatase↗
PubMed1983

[Acid phosphatases].

The authors discuss the pathological value of acid phosphatase measurement. One of its main applications is the diagnosis of prostatic cancer. The emergence of immunological methods of measuring the enzyme, which are more sensitive and more specific, has led to renewed interest as acid phosphatase measurement can now be used in the early diagnosis of prostatic cancer, or at least in the early diagnosis of its extraprostatic extensions.

Acid Phosphatase↗
PubMed1978

Phenotype dependence in the inhibition of red cell acid phosphatase (ACP) by folates.

Red cell acid phosphatase (ACP) is shown to be inhibited by folic acid and various folates. The degree of inhibition is phenotype dependent with a pattern of variation differing from that of the well recognized variation in red cell activity levels. The pattern of variation is ordered ACP1B less than ACP1A less than ACP1C in terms of the relative allelic contributions to the observed inhibition. This pattern correlates with previously observed patterns of risk for two hemolytic disorders and may thus provide a key to their understanding.

Acid Phosphatase↗
PubMed1987

Hydroxyl radical formation and iron-binding proteins. Stimulation by the purple acid phosphatases.

The effect of the purple acid phosphatases with binuclear iron centers (uteroferrin and bovine spleen phosphatase) on hydroxyl radical formation by iron-catalyzed Haber-Weiss-Fenton chemistry has been compared to that of lactoferrin and transferrin. Using 5,5-dimethyl-1-pyrroline-1-oxide to detect superoxide and hydroxyl radicals and the xanthine-xanthine oxidase system to generate superoxide and hydrogen peroxide, we have observed by ESR spectroscopy that both phosphatases were able to promote hydroxyl radical formation. Lactoferrin and transferrin were found incapable of giving rise to these reactive species. This can be explained by the fact that lactoferrin and transferrin carry two Fe(III) atoms per molecule, neither of which are readily reduced by biological reductants. In contrast, the phosphatases possess a binuclear iron center in which one of the iron atoms is stabilized in the ferric state, but the other freely undergoes one-electron redox reactions. The redox-active iron may act as a catalyst of the Haber-Weiss-Fenton sequence, thus enabling the reactions generating hydroxyl radical to proceed. The iron complex of diethylenetriamine penta-acetic acid, also redox active, was investigated and found as well to promote Haber-Weiss-Fenton chemistry.

Acid Phosphatase↗
PubMed1975

Correlation between erythromycin and acid phosphatase in mouse liver.

1. Whole liver homogenates obtained from mice 1h after an intraperitoneal injection of erythromycin lactobionate (343 mg/kg, 1/3 LD 50) were fractionated into nuclear (7000 times g min), mitochondrial (33000 times g min) and lysosomr-rich (250 000 times g min) fractions. 2. The resulting fractions, as well as the final supernatant, were analyzed for erythromycin, acid phosphatase and protein. 3. The highest relative specific activities (per cent total protein) of erythromycin and of acid phosphatase were exhibited by the lysosome-rich fraction. 4. It was of interest, therefore, to examine the effects of erythromycin upon the free activity of acid phosphatase in soluble form and on its in vitro and in vivo release from liver lysosomes. 5. Concentrations of 1.7 - 10-4 M, 3.4 - 10-4 M, 6.8 - 10-4 M and 13. 6 - 10-4 M of erythromycin lactobionate had no significant effect upon the free activity of acid phosphatase in soluble form but retarded the release of this enzyme from the liver lysosome-rich preparation. This effect of erythromycin lactobionate was dose- and time-dependent. 6. Treatment of mice with erythromycin lactobionate (343 mg/kg, 1/3 LD 50) iwtraperitoneally for 7 days significantly decreased the unsedimentable acid phosphatase activity expressed as per cent of total activity in whole liver homogenates. This indicated an in vivo diminished release of acid phosphatase from liver lysosomes by erythromycin. 7. Since erythromycin lactobionate is ionisable it could be possible that erythromycin basis as many other cationic molecules accumulates in lysosomes. 8. The in vitro and in vivo diminished release of acid phosphatase may suggest that erythromycin decreases permeability of lysosomal membrane.

Acid Phosphatase↗
PubMed1972

Location of acid phosphatase and -fructofuranosidase within yeast cell envelopes.

After 16 hr of incubation in a low-phosphate, aerated medium, bakers' yeast was obtained with a high titer of acid phosphatase (EC 3.1.3.2) and beta-fructofuranosidase (EC 3.2.1.26). All of the beta-fructofuranosidase and 75% of the acid phosphatase were easily released by mechanical disruption in a French pressure cell. The cell wall suffered a limited number of cracks, but this was sufficient for the co-release of these enzymes. Both enzymes were subject to autolytic release, although correlation was inconclusive because of the relative instability of acid phosphatase. The data are consistent with the bulk of the two enzymes being located in the periplasmic space. Ethylacetate treatments yielded ghosts with high beta-fructofuranosidase but low acid phosphatase activities. The surviving acid phosphatase was not representative of that in live cells. It was resistant to release by mechanical disruption and showed a high susceptibility to heat inactivation. The beta-fructofuranosidase in live cells and in ethylacetatetreated cells exhibited polydispersity in heat inactivation susceptibility; but the kinetics were indistinguishable, and facile release by mechanical disruption was shown in both cases.

Acetates↗
PubMed2001

A purple acid phosphatase from sweet potato contains an antiferromagnetically coupled binuclear Fe-Mn center.

A purple acid phosphatase from sweet potato is the first reported example of a protein containing an enzymatically active binuclear Fe-Mn center. Multifield saturation magnetization data over a temperature range of 2 to 200 K indicates that this center is strongly antiferromagnetically coupled. Metal ion analysis shows an excess of iron over manganese. Low temperature EPR spectra reveal only resonances characteristic of high spin Fe(III) centers (Fe(III)-apo and Fe(III)-Zn(II)) and adventitious Cu(II) centers. There were no resonances from either Mn(II) or binuclear Fe-Mn centers. Together with a comparison of spectral properties and sequence homologies between known purple acid phosphatases, the enzymatic and spectroscopic data strongly indicate the presence of catalytic Fe(III)-Mn(II) centers in the active site of the sweet potato enzyme. Because of the strong antiferromagnetism it is likely that the metal ions in the sweet potato enzyme are linked via a mu-oxo bridge, in contrast to other known purple acid phosphatases in which a mu-hydroxo bridge is present. Differences in metal ion composition and bridging may affect substrate specificities leading to the biological function of different purple acid phosphatases.

Acid Phosphatase↗
PubMed1964

EVIDENCE FOR AN EXOCELLULAR SITE FOR THE ACID PHOSPHATASE OF SACCHAROMYCES MELLIS.

Weimberg, Ralph (Northern Regional Research Laboratory, Peoria, Ill.), and William L. Orton. Evidence for an exocellular site for the acid phosphatase of Saccharomyces mellis. J. Bacteriol. 88:1743-1754. 1964.-Evidence is presented which demonstrates an exocellular location for acid phosphatase in Saccharomyces mellis. Derepressed intact cells exhibit acid phosphatase activity. The properties of the system are similar to those shown by the enzyme in cell-free extracts. There is no increase in total activity when cell-free extracts are prepared. Enzymatically active cell walls were prepared by leaching acetone-dried cells of this yeast in dilute acetate buffer (pH 6.5) plus beta-mercaptoethanol. The insoluble residue, consisting mainly of cell-wall material and containing the phosphatase, was treated with a variety of hydrolytic enzymes and other chemicals. Only papain and crude snail gut extracts dissociated the enzyme from the particulate fraction in nearly quantitative amounts. The mechanism of release by these two enzymes probably differs. Of all enzymes tested, only the snail gut extract digested the cell walls. By dividing the procedure for making protoplasts of S. mellis into two steps, acid phosphatase may be dissociated from resting cells and recovered as an active soluble enzyme. The first step is to pretreat the cells with a thiol reagent. The second step is to digest the cell wall by enzymes present in crude snail gut extracts. Arsenite must be included in the second step to protect the phosphatase from inactivation. The phosphatase is quantitatively released before the cell becomes osmotically fragile.

Acid Phosphatase↗
PubMedDate not supplied

Synovial fluid acid phosphatase in seropositive and seronegative arthritides.

Synovial fluid acid phosphatase was investigated in 82 arthritic patients with hydropsy in a knee joint. 39 of the patients were seropositive and 43 seronegative. 36 of the seropositive group had erosive rheumatoid arthritis. The mean synovial fluid acid phosphatase in the seropositive group, 11.6 U/l (SD +/- 8.4), was significantly higher (p less than 0.001) than in the seronegative group, 6.5 U/l (SD +/- 4.8).

Acid Phosphatase↗