Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:APRD00080 (Leaf)
 21,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The transport and phosphorylation of 2-deoxy-D-[3H]galactose in rabbit renal cortical cells was studied. 1. The uptake of 2-deoxy-galactose by cortical slices is associated with an appearance of both free and phosphorylated sugar in the cells. At 1 mM external sugar the cells establish a steady-state gradient of free 2-deoxy-galactose of 3.97 +/- 0.15 (23 animals). 2. The acid-labile sugar phosphate accumulated in the tissue has been identified by a combination of paper and radio-chromatography, as well as on the basis of some of its chemical properties, as 2-deoxy-D-galactose 1-phosphate. Ice-cold trichloroacetic acid produces a decomposition of this compound. 3. Increasing external pH (6-8) brings about a decrease in the steady-state levels of both free and phosphorylated sugar in slices. On the other hand, increasing pH activates the phosphorylation of 2-deoxy-D-galactose by a crude kinase in a tissue extract. 4. Sugar phosphate accumulated in the cells is dephosphorylated by the action of a Zn2+ -activated phosphatase. 5. The efflux of 2-deoxy-D-galactose from the cells is rather slow compared with that found for D-galactose. The efflux is associated with some dephosphorylation of cellular sugar phosphate, and some loss of 2-deoxy-galactose phosphate into the wash-out medium takes place. 6. An inhibition analysis of the uptake of 2-deoxy-D-galactose by the slices indicates that the transport site is shared by D-galactose. The following points of interaction between the sugar molecule and the carrier are identified: C1-OH, C3-OH and C4-OH (both axial) and C6-OH. A (pyranose) ring structure is also essential. A close packing between the substrate and the carrier in the vicinity of C2 is indicated. 7. The data suggest that the above transport system is localized predominantly at the antiluminal (basolateral) face of the renal tubular cells. While the detailed mechanism of the actual transport step (i.e. active transport of the free sugar, or by the action of a phosphotransferase) is still unclear, the data present evidence that both galactokinase and a Zn2+ -activated phosphatase participate in the maintenance of an intracellular steady state of the transported sugar.
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PMID:Transport and phosphorylation of 2-deoxy-D-galactase in renal cortical cells. 1 Sep 99

Antigenic analyses of Lactobacillus fermenti were carried out by double immunodiffusion in agar using extracts prepared with cold trichloroacetic acid (TCA) or hot dilute hydrochloric acid (HCL). A common antigen of L. fermenti, designated as antigen f by the author, was extracted from whole cells with dilute HCL, but not with TCA. The antigen f was also observed in Lactobacillus casei. In addition, all strains isolated from human saliva contained antigen 6 in their cell walls, while the antigen was not observed in most of the isolates from human feces. Therefore, L. fermenti could be divided into two subgroups based upon the existence of antigen 6. Antigen 7 which was demonstrated in some strains of L. fementi was shared by other species of lactobacilli belonging to the serological groups D and E. The common antigen 3 found in lactobacilli was extracted from all strains of L. fermenti Sugar components of cell walls were mainly galactose, glucose and glucosamine (including N-acetylglucosamine), but a small amount of rhamnose was present in the cell wall of only one strain. Inhibition tests with various sugars showed that the serologically active sugars were galactose for antigen f and glucose for antigen 6.
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PMID:Antigenic analyses of Lactobacillus fermenti. 5 Apr 68

Antigens specific for Lactobacillus acidophilus were investigated by double immunodiffusion in agar-gel. Antigenic materials were extracted from whole bacteria and some walls with cold trichloroacetic acid. Antisera were prepared by intravenous injection into rabbits of suspensions of whole organisms in solutions of bovine serum albumin, which had been heated and then washed. Four specific antigens were found as precipitinogens and denoted as antigens 11, 12, 13 and 14. Of 43 strains of L. acidophilus studied, 33 strains possessed antigen 11, six strains antigen 12, two strains antigen 13 and two strains antigen 14. Sugar compositions of wall preparations were analysed in an attempt to characterize the determinants of antigens 11 and 12. The walls contained glucose, galactose, hexosamine and sometimes glycerol, but no rhamnose was found. It was considered that alpha-glucopyranose was the major component of the determinant of antigen 11 since trehalose and maltose significantly inhibited the reaction between antibody 11 and its antigen; the determinant of antigen 12 was not clarified.
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PMID:Specific antigens of Lactobacillus acidophilus. 7 99

A field investigation was conducted to study the thermoregulatory responses in nine Japanese macaques (Macaca fuscata) living in a snowy mountain area, Jigoku-Dani (Hell Valley, about 1,000 m above sea level) in Shiga Heights in central Japan in late January 1975. At about the same time, a laboratory study was made on four Japanese macaques reared in mild climate in an outdoor cage in Inuyama City. In the Hell Valley (HV) monkeys, no significant change in metabolic rate was observed at Ta between -1.4 and 28.3 degrees C, while the rectal temperature was maintained at normal level. In the cold environment, the skin temperatures of HV monkeys were significantly higher than those of the monkeys living indoors previously studied. Similar patterns of metabolic and thermal responses were observed in Inuyama monkeys living outdoors, but to a lesser degree. The hair on the back and abdomen in the HV monkeys was significantly longer than that of Iuyama monkeys living indoors. It is suggested that the thick fur of HV monkeys may account for, if not all, the thermoregulatory responses of the Japanese macaque in snowy mountain areas.
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PMID:Thermoregulation of the Japanese macaque living in a snowy mountain area. 41 Sep 88

The three-dimensional crystal structure of bovine trypsinogen at approximately pH 7.5 was initially solved at 2.6 A resolution using the multiple isomorphous replacement method. Preliminary refinement cycles of the atomic coordinates trypsinogen have been carried out first to a resolution of 2.1 A, and later to 1.9 A, using constrained difference Fourier refinement; During the process, structure factors Fc and phi c were calculated from the trypsinogen structure and final interpretation was based on an electron-density map computed with terms (2 Fo - Fc) and phases phic at a resolution of 1.9 A. Crystals of trypsinogen grown from ethanol-water mixtures are trigonal with space group P3121, and cell dimension a = 55.17 A and c = 109.25 A. The structure is compared with the bovine diisopropylphosphoryltrypsin structure at approximately pH 7.2, oirginally determined from orthohombic crystals by Stroud et al. (Stroud, R.M., Kay L.M., and Dickerson, R.E. (1971), Cold Spring Harbor Symp. Quant. Biol. 36, 125-140; Stroud, R.M., Kay, L.M., and Dickerson, R.E. (1974), J. Mol. Biol. 83, 185-208), and later refined at 1.5 A resolution by Chambers and Stroud (Chambers, J.L., and Stroud, R.M. (1976), Acta Crystallogr. (in press)). At lower pH, 4.0-5.5 diogen, with cell dimensions a = 55.05 A and c = 109.45 A. This finding was used in the solution of the six trypsinogen heavy-atom derivatives prior to isomorphous phase analysis, and as a further basis of comparison between trypsinogen and the low pH trypsin structure. There are small differences between the two diisopropylphosphoryltrypsin structures. Bovine trypsinogen has a large and accessible cavity at the site where the native enzyme binds specific side chains of a substrate. The conformation and stability of the binding site differ from that found in trypsin at approximately pH 7.5, and from that in the low pH form of diisopropylphosphoryltrypsin. The catalytic site containing Asp-102, His-57, and Ser-195 is similar to that found in trypsin and contains a similar hydrogen-bounded network. The carboxyl group of Asp-194, which is salt bridged to the amino terminal of Ile-16 in native trypsin or other serine proteases, is apparently hydrogen bonded to internal solvent molecules in a loosely organized part of the zymogen structure. The unusually charged N-terminal hexapeptide of trypsinogen, whose removal leads to activation of the zymogen, lies on the outside surface of the molecule. There are significant structural changes which accompany activation in neighboring regions, which include residues 142-152, 215-550, 188A-195. The NH group of Gly-193, normally involved in stabilization of reaction intermediates (Steitz, T.A., Henderson, R., and Blow, D.M. (1969), J. Mol. Biol. 46, 337-348; Henderson, R. (1970), J. Mol. Biol. 54, 341-354; robertus, J.D., Kraut, J., Alden, R.A., and Birkoft, J.J. (1972), Biochemistry 11, 4293-4303) in the enzyme, is moved 1.9 A away from its position in trypsin...
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PMID:Structure of bovine trypsinogen at 1.9 A resolution. 55 51

The suitability of freeze-substitution in n-butanol and paraffin embedding of tissues for the histochemical demonstration of 5'-nucleotidase was investigated and compared with commonly used preparation techniques, such as fresh frozen sections and cryostate sections of cold formalin and glutaraldehyde-fixed rat liver. The influences of each step of the preparation techniques on the enzyme activity were controlled by a quantitative radiochemical assay. Freeze substitution was revealed to be superior to the commonly used preparation techniques with respect to: 1) high sensitivity and specificity of the histochemical 5'-nucleotidase reaction (this is based on the fact that incubation media with very low lead concentrations (0,6 mM/1) can be used); 2) excellent morphological appearance of the tissues showing cytological details of enzyme localization; 3) unlimited storage of the tissue materials and ease of sectioning.
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PMID:Freeze substituted tissue in 5'-nucleotidase histochemistry. Comparative histochemical and biochemical investigations. 57 82

The ultrastructural effects of dark, light, and low temperature were investigated in the cone cell endings of the red-eared turtle (Pseudemys scripta elegans). Thin sections revealed that in dark-adapted retinas maintained at 22 degrees C, the neural processes which contact the cone cells at the invaginating synapses penetrated deeply into the photoreceptor endings. When dark-adapted retinas were illuminated for 1 h at 22 degrees C, the invaginating processes were apparently extruded from the synaptic endings. On the other hand, 1-h exposure to a temperature of 4 degrees C in the dark caused the invaginating processes to become much more strikingly inserted than at room temperature. A morphometric analysis showed that the ratio between the synaptic surface density of the endings and their total surface density decreased in the light and increased in the dark and cold. Freeze-fracturing documented fusion of synaptic vesicles with the presynaptic membrane in all conditions tested. These observations suggest that the changes in configuration of the pedicles in the light, dark, and cold reflect a different balance between addition and retrieval of synaptic vesicle membrane from the plasmalemma; in the dark, the rate of vesicle fusion is increased, whereas in the cold, membrane retrieval is blocked. When the eyecups were warmed up and illuminated for 30-45 min after cold exposure, a striking number of vacuoles and cisterns appeared in the cytoplasm and coated vesicles were commonly seen budding from the plasmalemma. 60-90 min after returning to room temperature, the endings had reverted to their normal configuration, and the vast majority of vacuoles, cisterns, and coated vesicles had disappeared. When horseradish peroxidase was included in the incubation medium, very few synaptic vesicles were labeled at the end of the period of cold exposure. 30-45 min after returning to 22 degrees C, vacuoles and cisterns contained peroxidase, whereas most synaptic vesicles were devoid of reaction product. 2 h after returning to 22 degrees C, coated vesicles, vacuoles, and cisterns had disappeared and a number of synaptic vesicles were labeled. These experiments suggest that vacuoles, cisterns, and coated vesicles mediate the retrieval of the synaptic vesicle membrane that has been added to the plasmalemma during cold exposure.
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PMID:Membrane recycling in the cone cell endings of the turtle retina. 73 Jul 68

Freeze-fracture autoradiography (FFA) was introduced in 1976 as a new method for electron microscopic autoradiography of diffusible compounds (Fisher and Branton, Rix et al.). With the original technique, the film monolayer was applied to the cold specimen in a cryostat at atmospheric pressure. Coating under these conditions did not exclude the risk of artifacts, mainly due to uncontrolled ice contamination of the cold specimen surface. A new method has been developed for coating the frozen specimen, immediately after replication, in the maintained vacuum of the freeze-fracture unit. Two main components of the new technique are described in detail, a specially designed coating device, and the use of spreading substances, promoting adhesion of the film in vacuo. Using this technique artifacts so far inherent in the FFA method can be eliminated.
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PMID:Freeze-fracture autoradiography: the in-vacuo coating technique. 73 8

A revertible turbidity happens in the depectinized red raspberry juice under refrigeration. Its analysis is carried out: --Chemically: Total sugar determination by anthrone methol, galacturonic acid determination by carbazol, total nitrogen determination according to Berthelot's coloured reaction (automated analysis) -- Physically: Calcium, potassium and magnesium determinations by atomic absorption. -- Chromatographically: Sugar separation and determination by HPLC. M. W. determination of the different entites by GPC (gel Sephadex G 100). Pectic substances separation on DEAE-cellulose column. The turbidity ensues from an enhanced by cold and acidic pH flocculation process which occurs between the large nitrogeneous molecules (inactive and enzymic proteins mainly). M. W. (superior to 150.000) of the depectinizing preparation and rich in glucose and mannose polysaccharidiques (M. W. between the range from 1.000 to 10.000) accompanied by aldobiuronic units. The origin of the manno-glucan entity remains to be determined. It could be issued either a limit-substrate produced by the degradation of the raspberry pectic substances or an by Aspergillus niger excreted compound.
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PMID:[Proteo-polysaccharidic turbidity in depectinized raspberry juice]. 75 86

Freeze cleaving electron microscopy has shown that fusion of isolated secretory vesicles from bovine neurohypophyses was induced by Ca2+ in micromolar concentrations. Mg2+ and Sr2+ were ineffective. Mg2+ inhibited Ca2+-induced fusion. In suspensions containing secretory vesicles as well as sheets of cell membrane, release of vasopressin parallel to intervesicular fusion and fusion of secretory vesicles with sheets of cell membrane was observed after exposure to Ca2+. Mg2+ and Sr2+ were ineffective in replacing Ca2+ as trigger for fusion or vasopressin release. Intervesicular fusion and exocytotic profiles were observed when isolated neurohypophyses or neurosecretosomes were exposed to cold.
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PMID:Fusion of neurohypophyseal membranes in vitro. 90 83


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