Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A conventional brush border membrane preparation, obtained by divalent cation precipitation of homogenates of rabbit renal cortex, was analyzed by countercurrent distribution in an aqueous dextran:polyethylene glycol two-phase system. The resulting fractions were assayed for the presence of the Na+/H+ antiporter and for a variety of biochemical marker enzymes. This analysis revealed four physically distinct membrane populations (A-D). Population A consisted of two subpopulations, A' and A", which were enriched an average of 49-fold in maltase; they were also highly enriched in alkaline phosphatase, leucine aminopeptidase, and Na+/H+ antiporter. On the basis of their marker contents, populations A' and A" appear to represent highly purified, functional brush border membrane vesicles. Population B was enriched twofold in NADPH-cytochrome c reductase and population C was enriched 12-fold in galactosyltransferase. Populations B and C accounted for 25% of the protein in the starting material and appear to reflect contamination of the brush border membrane preparation by subpopulations of endoplasmic reticulum and Golgi fragments. Population D was enriched in Na+/H+ antiporter, alkaline phosphatase, leucine aminopeptidase, Na-K-ATPase, and acid phosphatase but not maltase, NADPH-cytochrome c reductase, galactosyltransferase, or succinate dehydrogenase. Its identity is unclear, and it might consist of a multiplicity of populations from different origins.
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PMID:Na+/H+ antiporter in membrane populations resolved from a renal brush border vesicle preparation. 633 Nov 75

As part of a six-month prospective study of the effects of neonatal thymectomy in the spontaneously diabetic BB Wistar rat, activities of the following enzymes were determined: alkaline phosphatase (AP), lactate dehydrogenase (LDH), creatine phosphokinase (CPK), glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT) and UDP-galactosyltransferase (UDPG). In prediabetics, AP and LDH levels were higher than in sham-operated, non-diabetic controls; however, this increase was seen in nearly all diabetes-prone BB rats, diminishing the usefulness of these changes in discerning potential diabetics from asymptomatic, diabetes-prone rats. After onset of the syndrome, there was a striking elevation of AP values in all diabetics with no similar alteration in asymptomatic, diabetes-prone rats suggesting this was a diabetes-related phenomenon. By contrast, UDPG was the only enzyme to decrease immediately following the onset of the syndrome. Both UDPG and AP levels correlated with blood glucose, the former negatively and the latter positively, suggesting a close relationship with changes occurring after onset of the syndrome. The remaining enzymes increased only in a portion of diabetics alone (GOT, GPT) or in a portion of both diabetics and asymptomatic, diabetes-prone BB rats (LDH, CPK).
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PMID:Serum enzymes in the BB rat before and after onset of the overt diabetic syndrome. 643 99

Previous studies have established the presence of polypeptide hormone receptors in Golgi fractions from rodent liver. In this study we attempted to identify peptide hormone receptors in other intracellular elements, particularly lysosomes. Tritosomes were prepared by a standard procedure, and highly purified secondary lysosomes were prepared by fractionating the L fraction of rat liver in a discontinuous metrizamide gradient into subfractions L1 to L4. Binding of 125I-labeled insulin and 125I-labeled somatotropin was studied with membranes prepared from osmotically shocked fractions. The L2 and L3 fractions, virtually devoid of galactosyltransferase (UDP galactose:2-acetamido-2-deoxy-D-glucosylglycopeptide galactosyltransferase, EC 2.4.1.38) but highly enriched in acid phosphatase [orthophosphoric-monoester phosphohydrolase (acid optimum), EC 3.1.3.2], appeared as classical secondary lysosomes by electron microscopy. When compared with Golgi fractions, the level of specific binding per 50 micrograms of protein of 125I-labeled somatotropin in L2 and L3 was 1/3, whereas that of 125I-labeled insulin was comparable. L1, which was reduced in acid phosphatase and increased in galactosyltransferase activities, showed higher hormone binding than did L2 and L3. This was not attributable to Golgi fraction contamination, as evident by specific binding/galactosyltransferase ratios. Binding to tritosome membranes could be largely accounted for by variable contamination with Golgi fractions as judged by specific binding/galactosyltransferase ratios. To clarify the distribution of receptor sites in lysosomal preparations, we fractionated the entire L fraction on a continuous Percoll gradient. Acid phosphatase and galactosyltransferase activities were segregated to the high and low density ranges of the gradient, respectively; however, the fractions enriched in hormone binding were of intermediate density, distinct from Golgi and lysosomal biochemical markers. We conclude that intracellular receptors are found not only in galactosyltransferase-containing very low density lipoprotein-marked Golgi vesicles but also in a unique vesicle of intermediate density between classical Golgi and lysosomal structures.
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PMID:Intracellular hormone receptors: evidence for insulin and lactogen receptors in a unique vesicle sedimenting in lysosome fractions of rat liver. 694 44

A method for the subcellular fractionation of rat liver using whole homogenates of rat liver and analytical sucrose density gradient centrifugation is presented. The distributions in the sucrose gradients of marker enzymes for all organelles have been determined for control homogenates and for homogenates prepared in the presence of selective membrane perturbants. This technique is not subject to potential loss of information inherent in the use of postnuclear supernatants as starting material for fractionation experiments. Particular attention has been paid to the distributions of putative plasma membrane marker enzymes, up to 50% of which may be found in the nuclear pellet. Gamma-Glutamyltransferase has been found to be entirely plasma membrane in location but has a different distribution pattern when compared with other plasma membrane markers. Particulate alkaline phosphatase and alkaline phosphodiesterase are shown to have bimodal distribution, one peak of which is coincident with 5'-nucleotidase. The other peak is coincident with that of the golgi marker, galactosyltransferase, but the membrane structure containing these activities shows characteristics of plasma membrane rather than golgi apparatus.
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PMID:Analytical subcellular fractionation of rat liver with special reference to the localisation of putative plasma membrane marker enzymes. 737 35

We present a comparative study of several biological markers (galactosyltransferase, CA 125, isoenzymes of amylase and alkaline phosphatase) with a view to ovarian carcinoma follow-up. Serum samples were obtained from a population of 75 patients under clinical observation. After a minimum 18-months period, we assessed the prognostic value of the markers. No marker permits the detection of discrete, evolving carcinomas. CA 125 is the marker that gives the best results, particularly in terms of sensitivity. Galactosyltransferase has a lower sensitivity except in the case of endometrioid carcinomas. Simultaneous analysis with CA 125 and galactosyltransferase results in no decisive improvement, other than greater precision in unfavourable prognoses. Isoenzymes of amylase and alkaline phosphatase are of no interest in the follow-up of such carcinomas.
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PMID:Biological markers and ovarian carcinomas: galactosyltransferase, CA 125, isoenzymes of amylase and alkaline phosphatase. 752 19

Linear and branched glycopeptides containing multiple sialyl-N-acetyllactosamine side chains have been synthesized using a combined chemical and enzymatic approach. Peptide backbones in which beta-GlcNAc-Asn residues were incorporated were obtained in good yields by optimized solid-phase synthesis following the Boc strategy. The resulting multivalent glycopeptides were galactosylated in near-quantitative yields using bovine galactosyltransferase, UDP-galactose, and calf alkaline phosphatase that destroys the inhibiting side product UDP. Subsequent enzymatic sialylation yielded the desired glycopeptides containing asparagine-linked sialyl-N-acetyllactosamine side chains. The compounds were characterized by 1H NMR and FABMS. Recombinant sialyltransferase and CMP-sialate synthetase were used for the enzymatic synthesis of sialosides on a preparative scale. The synthetic glycopeptides were tested as inhibitors of influenza virus to cells, revealing that most of the multivalent sialoglycopeptides exhibit increased binding that depends on the spacing when compared to monovalent compounds. A possible mechanism for increased binding is proposed.
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PMID:Chemical and enzymatic synthesis of multivalent sialoglycopeptides. 814 76

Galactosyltransferase is required for the addition of galactose to lactosylceramide (galactose beta 1-4 glucose beta 1-1 ceramide), resulting in the synthesis of globotriaosylceramide (Gb3). We describe a quantitative more sensitive and specific method for the measurement of UDP-galactose:lactosylceramide galactosyltransferase activities in rabbit small intestine and HeLa cell which utilizes the specific binding of Shiga toxin to the product, Gb3. Intestinal microsomal or HeLa cell sonicate preparations were incubated in the presence of lactosylceramide and [14C]UDP-galactose. The lipid reaction products were extracted on C18 Bond-Elut columns, separated by high-performance thin-layer chromatography and exposed to Shiga toxin followed by polyclonal rabbit anti-Shiga toxin antibody and goat anti-rabbit IgG alkaline phosphatase conjugate. Gb3 was visualized with NBT and BCIP and quantitated by densitometry. These data were compared with a standard assay in which, following incubation and lipid extraction, radioactivity was measured by scintillation counting of the isolated lipids. There was a 22-fold increase in enzyme activity by the immunostaining method compared to the usual scintillation counting technique. This is attributable to the exclusion of radioactive lipids other than Gb3 in calculating enzyme activity and the correction for endogenous UDP-galactose. Thus, the immunostaining method provides increased accuracy, sensitivity, and specificity in the assay of galactosyltransferase activity.
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PMID:A quantitative immunostaining method for the measurement of UDP-galactose:lactosylceramide galactosyltransferase for the synthesis of globotriaosylceramide in rabbit small intestine and HeLa cells. 825 Feb 38

The lacrimal glands of males and females of various species differ with respect to several morphological, biochemical and functional characteristics. The purpose of this study was to determine the effect of sexual maturation on Na+,K(+)-ATPase, muscarinic cholinergic receptors and beta-adrenergic receptors, which are closely related to the secretion of electrolytes and fluid by the gland, and on other membrane-associated enzymes, specifically galactosyltransferase and alkaline and acid phosphatase. Soluble and total membrane fractions were obtained from lacrimal glands of prepubertal (1.0 kg), pubertal (2 kg), and mature (4 kg) of New Zealand white rabbits of both sexes. Prepubertal and pubertal rabbits exhibited no sex differences in the total amount of lacrimal gland protein or in any of the enzymes or receptors, with the exception of galactosyltransferase and alkaline phosphatase. Galactosyltransferase had higher total and specific activities in prepubertal and pubertal males, and alkaline phosphatase had higher specific activity in prepubertal males. As animals matured, total protein and activities of the enzymes increased, and several quantitative differences between males and females became apparent. Samples from mature females contained significantly less DNA and membrane and total protein. Specific activities of Na+,K(+)-ATPase, cholinergic receptors, galactosyltransferase, and acid and alkaline phosphatase were 40% to 80% greater (p < 0.05) in mature females. Total and specific activity for beta-adrenergic receptors, on the other hand, were higher in the male rabbits. These findings suggest that sex hormones play a role in regulating the levels of expression of a number of enzymes and receptors, including several which are clearly involved in lacrimal secretory functions.
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PMID:Sex-dependent parameters related to electrolyte, water and glycoprotein secretion in rabbit lacrimal glands. 826 91

The Wilson disease adenosinetriphosphatase (ATPase; ATP7B) is believed to bind copper as Cu(I). We provide evidence to suggest that the ATPase actually transports Cu as Cu(II). When the copper is presented to rat liver microsomes as Cu(I), virtually all uptake is ATP independent. If the copper is presented as copper oxalate [Cu(II)], total uptake is reduced to approximately 10% of Cu(I) levels, but ATP-dependent uptake rises, both as a proportion of total uptake and in absolute terms. The reducing agent vitamin C and the Cu(I) chelator bathocuproine both override the effect of oxalate. The data indicate that there are two transporters in the microsomes, an ATP-independent Cu(I) transporter and an ATP-dependent Cu(II) pump. The activity of the Cu(I) transporter correlates most strongly with alkaline phosphatase, suggesting that it is derived from plasma membrane contamination. Cu(II) ATP-dependent transport correlates only with beta-1, 4-galactosyltransferase, which indicates that it is located in the Golgi apparatus.
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PMID:ATP-dependent copper transporter, in the Golgi apparatus of rat hepatocytes, transports Cu(II) not Cu(I). 894 86

Glycosyltransferases are normally synthesized as membrane-anchored proteins. However, we recently found that the murine enzyme UDP-Gal:Gal beta1 -->4GLcNAc (Gal to Gal) alpha1,3 galactosyltransferase (alpha1,3GT) is secreted in a soluble form into media by mouse teratocarcinoma F9 cells (Cho SK, Yeh J-C, Cho M, Cummings RD (1996) J Biol Chem 271: 3238-46). To study the biosynthesis of this enzyme and whether secretion of the soluble enzyme is a general phenomenon, a solid-phase assay was developed for the alpha1,3GT activity. A recombinant and soluble form of the murine alpha1,3GT was produced in H293 cells (H293-alpha1,3GT) to aid in optimizing the assay. Desialylated orosomucoid was used as an immobilized acceptor in coated microtiter plates. The formation of product was detected by a biotinylated human-derived anti-alpha-Gal IgG and streptavidin conjugated to either alkaline phosphatase or the recombinant bioluminescent protein aequorin. Enzyme activity was dependent on the concentrations of asialoorosomucoid, UDP-Gal, alpha1,3GT and the time of incubation. The assay was also useful in monitoring alpha1,3GT activity during enzyme enrichment procedures. Using this assay, we found that alpha1,3GT activity was present in both cell extracts and culture media of several mammalian cell lines. Enzyme activity was also present in the sera from several mammals, but activity was absent in the sera from either humans or baboons. Our results demonstrate the development of a novel assay for the alpha1,3GT and provide evidence that secretion of the enzyme is a common biological phenomenon.
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PMID:Secretion of alpha1,3-galactosyltransferase by cultured cells and presence of enzyme in animal sera. 951 86


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