Showing papers on "Alkaline phosphatase published in 1976"
TL;DR: Two metabolically distinct types of bone cell populations were isolated from mouse calvaria by a repetitive digestive procedure with a mixture of collagenase and trypsin, and it is postulate that the CT type of populations is enriched in osteoclasts and, possibly, osteocytes, and the PT type of population is enrichment in osteoblasts.
Abstract: Two metabolically distinct types of bone cell populations were isolated from mouse calvaria by a repetitive digestive procedure with a mixture of collagenase and trypsin. Cells released early in the digestion showed approximately two fold increases in cAMP when treated with either parathormone or calcitonin. These populations were denoted CT type. Later eluting cells showed larger parathormone-induced increases in cAMP but did not respond to calcitonin. These populations were denoted PT type. Six metabolic and enzymatic activities were measured in the two types of populations: acid and alkaline phosphatases, hyaluronate synthesis, citrate decarboxylation, prolyl hydroxylase, and general protein synthesis. Although each of these activities was present in both cell types, the basal levels of acid phosphatase and hyaluronate synthesis were higher in the CT cells, whereas alkaline phosphatase, citrate decarboxylation, and prolyl hydroxylase were higher in the PT cells. Parathormone stimulated acid phosphatase...
398 citations
TL;DR: The results suggest that phosphatidylinositol-specific phospholipase C can specifically act on plasma membrane of rat kidney slices.
240 citations
TL;DR: Na, K-ATPase rich membranes are shown to originate from the basal lateral plasma membranes by the patterns of labeling that were produced when either isolated cells or everted gut sacs were incubated with the slowly permeating reagent35S-p-(diazonium)-benzenesulfonic acid.
Abstract: A procedure was developed for the analytical isolation of brush border and basal lateral plasma membranes of intestinal epithelial cells. Brush border fragments were collected by low speed centrifugation, disrupted in hypertonic sorbitol, and subjected to density gradient centrifugation for separation of plasma membranes from nuclei and cole material. Sucrase specific activity in the purified brush border plasma membrane was increased fortyfold with respect to the initial homogenate. Basal lateral membrane were harvested from the low speed supernatant and resolved from other subcellular components by equilibrium density gradient centrifugation. Recovery of Na, K-ATPase activity was 94%, and 61% of the recovered activity was present in a single symmetrical peak. The specific activity of Na, K-ATPase was increased twelvefold, and it was purified with respect to sucrase, succinic dehydrogenase, NADPH-cytochromec reductase, nonspecific esterase, β-glucoronidase, DNA, and RNA. The observed purification factors are comparable to results reported for other purification procedures, and the yield of Na, K-ATPase is greater by a factor of two than those reported for other procedures which produce no net increase in the Na, K-ATPase activity. Na, K-ATPase rich membranes are shown to originate from the basal lateral plasma membranes by the patterns of labeling that were produced when either isolated cells or everted gut sacs were incubated with the slowly permeating reagent35S-p-(diazonium)-benzenesulfonic acid. In the former case subsequently purified Na, K-ATPase rich and sucrase rich membranes are labeled to the same extent, while in the latter there is a tenfold excess of label in the sucrase rich membranes. The plasma membrane fractions were in both cases more heavily labeled than intracellular protein. Alkaline phosphatase and calcium-stimulated ATPase were present at comparable levels on the two aspects of the epithelial cell plasma membrane, and 25% of the acid phosphatase activity was present on the basal lateral membrane, while it was absent from the brush border membrane. Less than 6% of the total Na, K-ATPase was present in brush border membranes.
228 citations
TL;DR: Observations indicate that VO3− can bind quite specifically at the phosphate-binding site on the enzyme, which suggests that the enzyme-complexed inhibitor may have some resemblance to the metastable intermediate formed during the hydrolysis of phosphate esters.
204 citations
TL;DR: N-Ethylaminoethanol proved superior to the now widely used diethanolamine buffer, especially for the enzymes from the intestine and placenta, behaving as an uncompetitive activator.
Abstract: I studied the kinetics and sensitivity toward inhibition by levamisole and R 8231 of the most important human alkaline phosphatase isoenzymes. N-Ethylaminoethanol proved superior to the now widely used diethanolamine buffer, especially for the enzymes from the intestine and placenta, behaving as an uncompetitive activator. The optimum pH largely depends on the substrate concentration. The addition of Mg2+ has no effect on the activities. The meaning of Km-values for alkaline phosphatases is questioned. Isoenzymes from human liver, bone, kidney, and spleen are strongly inhibited by levamisole or R 8231 at concentrations that barely affect the enzymes from intestine or placenta. The inhibition is stereospecific, uncompetitive, and not changed by Mg2+. Inhibition is counteracted by increasing concentrations of N-ethylaminoethanol. The mechanism of inhibition is suggested to be formation of a complex with the phosphoenzyme.
198 citations
TL;DR: The subcellular distribution of adenyl cyclase was investigated in small intestinal epithelial cells, suggesting a common localization on the plasma membrane.
176 citations
TL;DR: The development of necrosis in the pars recta appears to be a relatively late event, possibly due to further accumulation of Hg++ in this region, and the necrosis appears pathogenetically dissociable from the mechanism of acute renal failure.
Abstract: Acute renal failure was induced in male rats by the subcutaneous injection of 4 mg HgCl2 per kg body weight. Enzyme activities of the proximal tubule were studied histochemically at six time intervals from 15 min to 24 h. The enzymes studied were alkaline phosphatase, 5′-nucleotidase, acid phosphatase, α-glycerophosphate dehydrogenase (NAD-independent), malic dehydrogenase, succinic dehydrogenase, latic dehydrogenase, glucose-6-phosphate dehydrogenase and glucose-6-phosphatase. Decreases in activity were observed for alkaline phosphatase and 5′-nucleotidase after 15 min. Acid phosphatase was decreased after 30 min. These three enzymes returned to control levels after 3 h, but malic dehydrogenase and α-glycerophosphate dehydrogenase were decreased at this time interval. Succinic dehydrogenase was first decreased after 6 h. The earliest morphological changes detectable by light microscopy were observed in pars recta tubules in the medullary rays after 6 h, a time when all enzymes studied showed widespread decreased activity throughout the proximal tubule. After 24 h, the pars convoluta appeared morphologically normal but the pars recta was necrotic and exhibited calcification, whereas enzyme activity was decreased (absent in some cases) in both pars convoluta and pars recta.
151 citations
TL;DR: The 31P NMR line width of the E-P1 complex indicates that the dissociation of noncovalent phosphate is the rate-limiting step in the turnover of the enzyme at high pH.
Abstract: 31P nuclear magnetic resonance (NMR) was used to directly observe the binding of inorganic phosphate to alkaline phosphatase. Evidencq for the tight binding of 1.5-2.0 mol of inorganic phosphate per dimer of alkaline phosphatase is presented. Two distinct forms of bound phosphate are observed, one predominating above pH 7 and representing the non-covalent E-P1 complex and the other predominating below pH 5 and representing the covalent E-P1 complex. The 31P NMR line width of the E-P1 complex indicates that the dissociation of noncovalent phosphate is the rate-limiting step in the turnover of the enzyme at high pH.
132 citations
TL;DR: 19F nuclear magnetic resonance (NMR) spectroscopy results lead directly to the conclusion that dissociation of noncovalently bound inorganic phosphate from the enzyme is the rate-limiting process in enzyme catalysis at high pH.
Abstract: 19F nuclear magnetic resonance (NMR) spectroscopy has been used to study a fully active E. coli fluorotyrosine alkaline phosphatase. The fluorotyrosine resonances provide sensitive probes of the conformational states of the protein. They were used to follow the addition of zinc or cobalt to the apoprotein, and the titration of the protein with inorganic phosphate or the inhibitor 2-hydroxy-5-nitrobenzylphosphonate. The results indicate that 2 molecules of inorganic phosphate per dimer of alkaline phosphatase are required to complete a general conformational change in the protein involving perturbations to the environment of several tyrosines. Spectra of the cobalt enzyme indicate that on specific tyrosine per subunit may be near the metal site. The 19F NMR results, combined with the 31P NMR results in the accompanying paper, lead directly to the conclusion that dissociation of noncovalently bound inorganic phosphate from the enzyme is the rate-limiting process in enzyme catalysis at high pH. The local environment of the individual fluorotyrosines is also discussed.
117 citations
TL;DR: The organic phosphate bound to these phosphoproteins was shown to be directly responsible for the formation of the apatite phase, since removal of 60% of the covalently bound phosphate with alkaline phosphatase destroyed the protein's ability to induce hydroxylapatite formation.
Abstract: (Ethylenedinitrilo)tetraacetic acid soluble phosphoproteins were isolated from rat incisor and bovine unerupted teeth. This material was examined for its effect on the stability of amorphous calcium phosphate in vitro. When the precipitation of amorphous calcium phosphate was attempted in the presence of small amounts of these phospho-proteins, an apatite-like mineral was observed to form, which was approximately 60% crystalline, as determined by infrared measurements. This apatite phase could not be induced by addition of phosphoprotein after the precipitation reaction. The organic phosphate bound to these phosphoproteins was shown to be directly responsible for the formation of the apatite phase, since removal of 60% of the covalently bound phosphate with alkaline phosphatase destroyed the protein's ability to induce hydroxylapatite formation. The properties of the dental phosphoproteins appear to be consistent with their possible involvement in the development of the mineral phase of dentine.
112 citations
TL;DR: 125I-wheat germ agglutinin provides a highly useful tool for the detection of microgram quantities of plasma membrane components which should be applicable to many other systems as well.
Abstract: Methods have been developed for the isolation on a semi-micro scale of a plasma membrane-enriched fraction from rat islets of Langerhans. An important feature of these experiments is the use of 125I-labeled wheat germ agglutinin as a specific probe for plasma membrane-containing fractions. The partly purified plasma membrane fraction had a density in sucrose of about 1.10 and was enriched in the activities of 5'-nucleotidase, alkaline phosphatase, sodium-potassium, and magnesium-dependent ATPase and adenylate cyclase. It contained only very low levels of acid phosphatase, cytochrome c oxidase, insulin, and RNA. Further purification was hampered by the relatively small amounts of fresh plasma membrane material that could be obtained from 16-24 rats in each experiment. When islets were prelabeled with radioactive fucose, the plasma membrane-enriched fraction contained radioactivity at a four- to fivefold higher specific acivity than the whole islet homogenate. Sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis of plasma membrane-enriched fractions pooled from several experiments revealed a distinctive pattern of protein bands as compared with other less pure fractions. With respect to rapidity, apparent specificity, and easy reversibility of the labeling of the plasma membrane fraction, 125I-wheat germ agglutinin provides a highly useful tool for the detection of microgram quantities of plasma membrane components which should be applicable to many other systems as well.
TL;DR: Initial studies indicated that bone and cartilage, when treated with a hypertonic glutaraldehyde fixative for a short period, retained significant enzyme activity for histochemistry and also maintained excellent fine structure.
Journal Article•
TL;DR: It is hypothesized that the alkaline phosphatase of human tumor tissues reflects the expression of placental genes corresponding to one or more phases of trophoblastic development.
Abstract: Summary Alkaline phosphatase electrophoretic patterns characteristic of three phases in early human trophoblast development are described in this preliminary communication. Phase 1 (6 to 10 weeks) consists entirely of two heat-sensitive, l-homoarginine-inhibited bands, the slower one of which possesses antigenic determinants of liver-bone-type alkaline phosphatase, whereas the fast band lacks any of the known alkaline phosphatase antigenic determinants. Phase 2 pattern (11 to 13 weeks) is that of a mixture of Phase 1 and Phase 3 isozyme components, the latter exhibiting two isozyme bands with the characteristics of term placental alkaline phosphatase. These three patterns of developmental phase-specific placental alkaline phosphatases correspond in order to non-Regan isoenzyme, a mixture of Regan and non-Regan isozymes and Regan isoenzyme in a variety of human cancer tissues. The biochemical profile characteristic of trophoblast developmental Phase 1 alkaline phosphatase is expressed as 78.5% heat-sensitive inhibition (5 min at 65°), 66.3% l-homoarginine inhibition, and 17.3% l-phenylalanine inhibition where n = 12. It is hypothesized that the alkaline phosphatase of human tumor tissues reflects the expression of placental genes corresponding to one or more phases of trophoblastic development.
TL;DR: Patients with prostatic adenocarcinoma classified on the basis of whether or not their bone scans were positive for metastasis had no bone pain, and had normal acid and alkaline phosphatase levels and clinical evaluations for bone metastases were reviewed.
Abstract: Patients (219) with prostatic adenocarcinoma were classified on the basis of whether or not their bone scans were positive for metastasis. Acid and alkaline phosphatase cleterminations and clinical evaluations for bone metastases were reviewed. Of those with proved metastases, 43% had no bone pain, 39% had normal acid phosphatase levels, 23% normal alkaline phosphatase levels, 19% normal levels of both enzymes, and 15% normal enzyme levels without bone pain. Twenty-four per cent of the patients with normal enzyme levels and clinically unsuspected bone metastases had bone scans which proved positive for metastasis; 62% of these had normal radiographs.
TL;DR: It is suggested that the marked lysosomal activity during early pregnancy is related to the architectural refashioning of the placenta during this period and that there are two phosphatase-linked transfer systems in the trophoblast, one dependent upon acid-phosphatases-containing multivesicular bodies and being utilised during earlyregnancy and the other reliant upon alkaline phosphatases and dominating during the second half of gestation.
Abstract: The subcellular localisation of acid and alkaline phosphatase has been studied in the trophoblast of placentae from both normal and complicated pregnancies. In placentae from uncomplicated pregnancies the number of trophoblastic acid-phosphatase-containing organelles decreases progressively as gestation proceeds whilst alkaline-phosphatase activity, although abundant at term, could not be demonstrated during the early stages of pregnancy. The acid-phosphatase-containing organelles are of two types; one is a small round body which is probably a lysosome whilst the other is a multivesicular body. The alkaline phosphatase is distributed mainly on the syncytial microvilli and plasma-membrane. It is suggested that the marked lysosomal activity during early pregnancy is related to the architectural refashioning of the placenta during this period and that there are two phosphatase-linked transfer systems in the trophoblast, one dependent upon acid-phosphatase-containing multivesicular bodies and being utilised during early pregnancy and the other reliant upon alkaline phosphatase and dominating during the second half of gestation. In placentae from prolonged pregnancies there is a further decrease in trophoblastic acid phosphatase and, usually, a continuing increase in alkaline-phosphatase activity. In placentae from babies of low birth weight this trend is sometimes reversed and alkaline-phosphatase activity either disappears or its reaction product diffuses throughout the syncytium; this is usually accompanied by a marked increase in the number of acid-phosphatase-containing multivesicular bodies. Placentae from women with pre-eclampsia show no loss of alkaline-phosphatase activity but are characterised by an increased number of lysosomal bodies.
TL;DR: It is determined that the phoS protein is a component of periplasmic protein band P4 described by Morris et al. (1974) and its synthesis is sensitive to the concentration of phosphate in the growth medium.
Abstract: Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunological techniques, we have compared the synthesis of the phoA protein (alkaline phosphatase) and the phoS protein (phosphate-binding protein) in response to the level of phosphate in the medium in different genetic backgrounds containing the known alkaline phosphatase control mutations. Both proteins are produced in excess phosphate media in a phoR1a- strain, whereas neither protein is produced in a phoB- strain even under derepression conditions. In four different phoR1c- strains, however, the phoA product cannot be detected in extracts of cells obtained from any growth condition, whereas the phoS product is produced in both excess and limiting phosphate media. It is not yet known if phoR1c- mutants are a special class of mutations within the phoB gene or whether they occur in a separate cistron involved in alkaline phosphatase regulation. From these results we conclude that the expression of the phoA gene is not always co-regulated with expression of the phoS gene product. We have determined that the phoS protein is a component of periplasmic protein band P4 described by Morris et al. (1974). The phoS product lacks sulfur-containing amino acids and is extractable by treatment with polymyxin sulfate. The other component of band P4 contains methionine and/or cysteine and is not extracted by polymyxin sulfate treatment. Like the phoS and phoA proteins, its synthesis is sensitive to the concentration of phosphate in the growth medium. In addition, the existence of a new class of periplasmic proteins synthesized at maximum rate in high phosphate media is demonstrated.
TL;DR: Both the fasting and the postprandial serum bile acid concentrations tended to be more sensitive tests of hepatobiliary disease than bilirubin, ASAT and ALAT.
Abstract: An enzymatic-fluorimetric method using a highly purified 3alpha-hydroxysteroid dehydrogenase (Sterognost-3alpha, Nyco) was used to determine fasting serum bile acid concentrations on 49 occasions in 43 patients with various liver diseases. A two-hour postprandial bile acid determination was carried out on 29 occasions in 27 of the patients. Fasting bile acid concentration correlated significantly both in cholestatic hepatobiliary and in parenchymatous liver disease to serum bilirubin and aspartate aminotransferase (ASAT) but not to alanine aminotransferase (ALAT), alkaline phosphatase, or albumin. The two-hour postprandial bile acid concentration was above normal in all patients with biochemical and/or histological signs of hepatobiliary disease, also when fasting concentration was within normal limits. In parenchymatous liver disease correlations existed between the two-hour postprandial bile acid concentration and bilirubin, ASAT, and ALAT. The sensitivity of serum bile acid estimation was compared to other liver function tests. Both the fasting and the postprandial serum bile acid concentrations tended to be more sensitive tests of hepatobiliary disease than bilirubin, ASAT and ALAT.
TL;DR: Alkaline phosphatase from human liver was purified to homogeneity and the desialylated enzyme was more readily denatured by sodium dodecyl sulphate in the presence of mercaptoethanol than was the native enzyme.
Abstract: Alkaline phosphatase from human liver was purified to homogeneity. The purification procedure included solubilization with butanol, fractionation with acetone, and chromatography on concanavalin A-Sepharose, DEAE-cellulose, Sephadex G-200 and DEAE-Sephadex. Purity was established by standard and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The isoelectric point of the protein was determined to be 4.0. Sephadex-gel filtration gave a mol.wt. of 146000, although a higher value was obtained in the presence of 100mM-NaC1. The subunit mol.wt. 76700, was determined by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Neuraminidase treatment resulted in two enzyme-activity bands on isoelectric-focused gels with isoelectric points of 6.6 and 6.8. The desialylated enzyme gave only one protein band on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis with a subunit molecular weight indistinguishable from that of the non-neuraminidase-treated protein. The desialylated enzyme was more readily denatured by sodium dodecyl sulphate in the presence of mercaptoethanol than was the native enzyme.
TL;DR: Patients with widespread metastases had significantly higher isoenzyme II levels than those with no metastases or with limited local spread, and further studies will be necessary to evaluate the clinical usefulness of this serum galactosyltransferase isoen enzyme in the diagnosis and monitoring of patients with neoplastic disease.
Abstract: Galactosyltransferase activity was assayed in sera from 58 patients with various types of cancer. On discontinuous polyacrylamide gel electrophoresis a slow-moving peak of galactosyltransferase activity (isoenzyme II) was found to be present in the serum of 43 of these patients in addition to the major isoenzyme I. Isoenzyme II was found in only 2 of 39 patients with various nonmalignant disorders and was not detected in the serum of 22 normal control subjects. There was no correlation between the presence of this electrophoretically distinct isoenzyme and total serum galactosyltransferase activity, alkaline phosphatase, levels of carcinoembryonic antigen, or blood type. However, patients with widespread metastases had significantly higher isoenzyme II levels than those with no metastases or with limited local spread. Further studies will be necessary to evaluate the clinical usefulness of this serum galactosyltransferase isoenzyme in the diagnosis and monitoring of patients with neoplastic disease.
TL;DR: The concept that membrane gamma-GT may be involved in amino acid and dipeptide uptake, and indicate that further investigation of such involvement may be conveniently pursued using mammalian small bowel, is supported.
TL;DR: A microvillus plasma membrane-enriched fraction of human placenta was obtained by a combination of differential, isopycnic, and rate-zonal centrifugation techniques and indicated a relative enrichment of plasma membrane between 10- and 20-fold over the most prominent contaminating enzyme markers.
TL;DR: The results confirm the reports suggesting that plasma membrane is the major site of alkaline phosphatase localization in HeLa cells and indicates that the mitochondrial localization of the Regan isoenzyme reported in ovarian cancer may not be a common phenomenon in Regan-producing cancer cells.
Abstract: The localization of alkaline phosphatase in HeLa cells was examined by electron microscopic histochemistry and subcellular fractionation techniques. Two monophenotypic sublines of HeLa cells which respectively produced Regan and non-Regan isoenzymes of alkaline phosphatase were used for this study. The electron microscopic histochemical results showed that in both sublines the major location of alkaline phosphatase is in the plasma membrane. The enzyme reaction was occasionally observed in some of the dense body lysosomes. This result was supported by data obtained from a subcellular fractionation study which showed that the microsomal fraction rich in plasma membrane fragments had the highest activity of alkaline phosphatase. The distribution of this enzyme among the subcellular fractions closely paralleled that of the 5’-nucleotidase, a plasma membrane marker enzyme. Characterization of the alkaline phosphatase present in each subeellular fraction showed identical enzyme properties, which suggests that a single isoenzyme exists among fractions obtained from each cell line. The results, therefore, confirm the reports suggesting that plasma membrane is the major site of alkaline phosphatase localization in HeLa cells. The absence of any enzyme reaction in the perimitochondrial space in these cultured tumor cells also indicates that the mitochondrial localization of the Regan isoenzyme reported in ovarian cancer may not be a common phenomenon in Regan-producing cancer cells.
TL;DR: Recessive mutants defective in the formation of non-specific alkaline phosphatase (EC 3.3.1.1) could be selected by staining colonies on a plate with p-nitrophenylphosphate after treatment with chloroform vapour, although a significant basal level of the enzyme activity was observed in the repressed condition.
TL;DR: Men showed a significantly higher excretion of gamma-glutamyltransferase, alpha-glucosidase, trehalase, N-acetyl-beta-glUCosaminidase and leucine arylamidase activity than did women if enzyme activity was related to urinary time volume, if urinary creatinine was used as the basis of reference.
Abstract: Urinary excretion of lactate dehydrogenase, hydroxybutyrate dehydrogenase, gamma-glutamyltransferase, alkaline phosphatase, arylsulphatase A, alpha-glucosidase, beta-galactosidase, trehalase, N-acetyl-beta-glucosaminidase, beta-glucuronidase, and leucinearylamidase was studies in a carefully selected group of 100 healthy subjects, 50 women and 50 men. Enzyme activities were assayed in 3-h morning samples after gel filtration of the urine. Activities were related to time volume, and to urinary creatinine concentration. Several transforming functions had to be applied to enzyme output data to obtain an approximation to gaussian frequency distribution. Men showed a significantly higher excretion of gamma-glutamyltransferase, alpha-glucosidase, trehalase, N-acetyl-beta-glucosaminidase,beta-glucuronidase, and leucine arylamidase activity than did women if enzyme activity was related to urinary time volume. Women excreted more lactate dehydrogenase, hydroxybutyrate dehydrogenase, gamma-glutamyltransferase, alkaline phosphatase, alpha-glucosidase, trehalase, and N-acetyl-beta-glucosaminidase activity than did men, if urinary creatinine was used as the basis of reference. Reference intervals were calculated as 2.5 and 97.5 percentiles for both sexes.
TL;DR: The unicellular alga Chlamydomonas reinhardi produces two constitutive acid phosphatases and three depressible phosphatase that can utilize napthyl phosphate as a substrate that differ in their heat sensitivity and affinity for glycerophosphate.
Abstract: The unicellular alga Chlamydomonas reinhardi produces two constitutive acid phosphatases and three depressible phosphatases (a neutral and two alkaline ones) that can utilize napthyl phosphate as a substrate. Specific mutants depressible phosphatase were used to investigate biochemical properties and the cytochemical localization of these enzymes. The two constitutive phosphatases show similar pH optima (about 5.0) and Km values (2 x 10(-3) to 3.3 x 10(-3) M) but differ in their heat sensitivity and affinity for glycerophosphate.
Journal Article•
TL;DR: Only in cancers of the ovaries did a positive correlation between this enzyme marker and the extent of the disease be found, and in more than one-third of the patients examined, PLAP levels were an index of the tumor burden.
Abstract: In 302 patients with tumors of the cervix, corpus uteri, and ovaries, assessment by clinical staging (tumors-nodules-metastasis system) (4) and histopathology has been related to the presence of serum heat-stable, placenta-like alkaline phosphatase (PLAP) activity.
Early stages of cervical tumors show the highest incidence of this isoenzyme. In advanced stages of this disease, a decrease in frequency was observed that might be interpreted as the result of gradual dedifferentiation of the tumor cells to a point where synthesis of PLAP became undetectable. The same observation was made in adenocarcinomas of the corpus uteri, i.e. , patients with advanced disease tended to have the lowest incidence of serum PLAP.
Only in cancers of the ovaries did we find a positive correlation between this enzyme marker and the extent of the disease. In more than one-third of the patients examined, PLAP levels were an index of the tumor burden.
TL;DR: The results indicated a different peptide structure for each, based upon HB2-terminal residue sequence, two-dimensional tryptic peptide maps, and different amino acid compositions, which is interpreted to indicate that the enzymes are synthesized by different structural genes.
Abstract: Human liver alkaline phosphatase [ortho-phosphoric monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1] was purified, and some of its physical and chemical properties were examined and compared to those of human placental alkaline phosphatase. The results indicated a different peptide structure for each, based upon HB2-terminal residue sequence, two-dimensional tryptic peptide maps, and different amino acid compositions. These data are interpreted to indicate that the enzymes are synthesized by different structural genes. Other molecular properties differentiating the two enzymes were a higher apparent molecular weight for the liver enzyme from sodium dodecyl sulfate gel electrophoresis, a higher S20,w value, different carbohydrate content, and a different isoelectric point. The immunochemical specificity of each enzyme was not affected by removal of sialic acid groups. Both enzymes are similar in that they are dimers of equal molecular weight subunits, and are probably homodimers.
TL;DR: A solid phase antibody assay by means of alkaline phosphatase conjugated to antiimmunoglobulin is described, which indicated that serum samples could be collected at intervals of three to six days only to reach a serological diagnosis in clinical patients.
Abstract: A solid phase antibody assay by means of alkaline phosphatase conjugated to antiimmunoglobulin is described. Specially designed microcuvettes were sensitized with influenza A antigen, and antibodies bound to it were assayed by anti-IgG alkaline phosphatase conjugate in a semiautomated photometer equipped with a programmable calculator. The sensitivity was found to be 200 times higher than HI- or CF-techniques, and the interassay variation was so small that twofold changes in antobody activity could be regarded as significant. Results from vaccinees indicated that serum samples could be collected at intervals of three to six days only to reach a serological diagnosis in clinical patients.
TL;DR: Blood samples from 2 camels, 1 guanaco and 1 llama were studied and platelets from camilidae aggregated with ADP, collagen or ristocetin, which showed high levels of phosphorus, calcium, sodium and the enzymes alkaline phosphatase, CPK, LDH and SGOT.