Showing papers on "Melibiose published in 1989"
TL;DR: A model proposing that phosphorylation state changes in the GAL4 protein are key to modulating its activity is presented, showing evidence that the galactose- and glucose-triggered GAL 4 protein mobility shifts are due to post-translational modification.
Abstract: In yeast, galactose triggers a rapid GAL4-dependent induction of galactose/melibiose regulon (GAL/MEL) gene transcription, and glucose represses this activation. We discovered that alterations in the physical state of the GAL4 protein correlate with activation and repression of the GAL/MEL genes. Using Western immunoblot assay, we observe two electrophoretic forms of GAL4 protein-GAL4I and GAL4II-in noninduced cells. In the absence of glucose, the addition of galactose to such cells results in the rapid appearance of a third and slower-migrating form, GAL4III, which differs from at least GAL4I by phosphorylation. GAL80-deletion cells that constitutively transcribe galactose-responsive genes due to the lack of the GAL80 protein, an antagonist of the GAL4 protein, exhibit GAL4III without galactose addition. Addition of glucose, which results in rapid repression of galactose gene transcription, triggers a rapid elimination of GAL4III and an increase in GAL4II. Cycloheximide experiments provide evidence that the galactose- and glucose-triggered GAL4 protein mobility shifts are due to post-translational modification. GAL4III is labeled with [32P]phosphate in vivo; in vivo 35S-labeled GAL4III could be converted by phosphatase treatment in vitro to GAL4I. We present a model proposing that phosphorylation state changes in the GAL4 protein are key to modulating its activity.
88 citations
TL;DR: P Phenotypic and DNA relatedness data indicated that a group of organisms referred to as Enteric Group 47 orKlebsiella Group 47 at the Centers for Disease Control (Atlanta, Georgia) was identical with K. ornithinolytica.
Abstract: The nameKlebsiella ornithinolytica sp. nov. is proposed for a group ofKlebsiella strains referred to previously as NIH Group 12 at the National Institute of Health, Tokyo. The members of this species are Gram-negative, encapsulated, nonmotile rods with the general characteristics of the familyEnterobacteriaceae and of the genusKlebsiella. They give positive results in tests for indole production, Voges-Proskauer, citrate utilization, lysine and ornithine decarboxylases, urease, β-galactosidase, malonate utilization, growth in KCN, and esculin hydrolysis, and they produce acid and gas fromd-glucose, and acid froml-arabinose, cellobiose, lactose, melibiose, raffinose, rhamnose, sucrose, trehalose,d-xylose, adonitol,d-arabitol, myo-inositol, sorbitol, arbutin, salicin, α-methyl-d-glucoside, and mucate. They give negative drolysis, DNase, pectinase, and acid production fromd-arabinose, melezitose, and dulcitol. They can grow at 4°C and 42°C, and do not produce any pigment. DNA relatedness of eight strains ofKlebsiella ornithinolytica to three strains including the type strain of this species averaged 88% in reaction at 75°C. DNA relatedness to the already recognizedKlebsiella species inEnterobacteriaceae was 1 to 20%. Phenotypic and DNA relatedness data also indicated that a group of organisms referred to as Enteric Group 47 orKlebsiella Group 47 at the Centers for Disease Control (Atlanta, Georgia) was identical withK. ornithinolytica. The type strain ofK. ornithinolytica is NIH 90-72 (JCM 6096).
75 citations
Patent•
27 Mar 1989
TL;DR: A material which has the ability to effect it's passage, at least in part, and the ability of transport other materials through the blood-brain barrier is a material which includes any one or more pure sugars or pure amino sugars from the group consisting of meso ethritol, zylitol, D(+) galactose, D+ lactose, dulcitol, myo-insoitol, L(−) fructose, D−) mannitol, sorbitol, D
Abstract: A material which has the ability to effect it's passage, at least in part, and the ability to transport other materials through the blood-brain barrier which includes any one or more pure sugars or pure amino sugars from the group consisting of meso ethritol, zylitol, D(+) galactose, D(+) lactose, D(+) xylose, dulcitol, myo-insoitol, L(−) fructose, D(−) mannitol, sorbitol, D(+) glucose, D(+) arabinose, D(−) arabinose, celloboise, D(+) maltose, D(+) raffinose, L(+)rhamnose, D(+) melibiose, D(−) ribose, adonitol, D(+) arabitol, L(−) arabitol, D(+) fucose, L(−) fucose, D(−) lyxose, L(+) lyxose, L(−) lyxose, D(+) glucosamine, D mannosamine, and D galactosamine; and any one or more amino acids from the group consisting of arginine, asparagine, aspartic acid, cysteine, glutamic acid, glycine, histidine, leucine, methionine, phenylalanine, proline, serine, threonine, glutamine, lysine, tryptophan, tyrosine, valine, and taurine. For use in the research or treatment of a subject that material is combined with one or more of the substances beta carotene, xanthophyll, lecithin, calcium, somatostatin, vasopressin, endorphin, enkephalin, acetyl-L-carnitine, GABA, dynorphin, L-tryptophan, choline, thiamine, pyridoxine, niacin, L-arginine, hydroxyproline, NGF, methionine, cystine, potassium, phosphorus, chlorine, sodium, vitamins A, B, C, D and E, and selenium.
75 citations
TL;DR: It is concluded that although histidine 322 is important for energy transduction, neither an electronegative atom nor a dissociable proton is essential for proton cotransport with lactose or melibiose.
54 citations
TL;DR: In this paper, the results of the Maillard reaction between various reducing sugars and amino acids were investigated by measuring several properties of the sugar-protein Maillard adducts after each sugar was kept with ovalbumin at 50 OC and 65% RH for 0-20 days, and the results indicated that the terminal pyranoside groups bonded at the C 4 OH of glucose retarded further degradation to aldehyde components of their Amadori rearrangement products.
Abstract: The Maillard reaction of ovalbumin and several disaccharides (maltose, cellobiose, isomaltose, lactose, melibiose) having glucose at the reducing end was investigated by measuring several properties of the sugar-protein Maillard adducts after each sugar was kept with ovalbumin at 50 OC and 65% RH for 0-20 days. Isomaltose and melibiose mixed with the protein strongly induced brown colorization, production of fluorescent compounds, and protein polymerization, whereas maltose, cellobiose, and lactose did so very weakly. All five of the sugars decreased free amino groups of the protein to less than 20% within 1 week. The weaker production of advanced Maillard reaction products such as brown color and/or fluorescent compounds in the maltose, lactose, and cellobiose systems indicated that the terminal pyranoside groups bonded at the C-4 OH of glucose retarded further degradation to aldehyde components of their Amadori rearrangement products. Earlier studies on the reaction between various reducing sugars and amino acids showed that the rates of the coupling reaction between amino and carbonyl groups and the browning reaction observed at advanced stages of the reaction were affected by the chemical structure of sugars and amino acids (e.g., Lewis and Lea, 1950; Pomeranz et al., 1962; Burton and McWeeney, 1963).
45 citations
TL;DR: It is concluded that the presence of a histidine residue at position 322 of the lactose carrier is not obligatory for H+ transport per se, and the mutants cloned by a novel 'sucrose marker exchange' method retain the capacity to carry out facilitated diffusion with lactose or melibiose.
45 citations
TL;DR: A topological model for the melibiose carrier with 10 or 12 transmembrane domains is supported, which dictates that the protein cross the membrane an even number of times.
42 citations
TL;DR: A model is presented which depicts the binding of galactosides to the lactose permease, and neither the specific structure of the aglycone nor its relative hydrophobicity appeared to be important factors in permease recognition.
36 citations
TL;DR: Measurement of sugar transport and cation-coupling characteristics indicate that the carboxyl tail plays no direct role in substrate recognition or energy transduction, and is consistent with the hypothesis that the sugar/cation binding site is formed by the interaction of the transmembrane helices 3, 4, 6, 9, and 10 and does not involve the car boxyl-terminal portion of the protein.
19 citations
TL;DR: It is hypothesized that melibiose use by S. mutans requires the interaction of the GtfA enzyme, or another gene product under the control of the gtfA promoter, with other gene product(s) involved inmelibiose transport or hydrolysis.
Abstract: The Streptococcus mutans serotype c gtfA gene encodes a 55-kilodalton sucrose-hydrolyzing enzyme. Analysis of S. mutans gtfA mutants revealed that the mutant strains were specifically impaired in the ability to use melibiose as a sole carbon source. S. mutans gtfA mutant strains synthesized less alpha-galactosidase activity inducible by raffinose than wild-type strains. Melibiose (an inducer in wild-type strains) failed to induce significant levels of alpha-galactosidase in the mutant strains. We hypothesize that melibiose use by S. mutans requires the interaction of the GtfA enzyme, or another gene product under the control of the gtfA promoter, with other gene product(s) involved in melibiose transport or hydrolysis.
8 citations
TL;DR: Carrot (Daucus carota L.) cell suspension cultures grew well when provided with glucose, fructose, sucrose or raffinose, but supported less growth unless supplemented with glucose or fructose, and 2-deoxy-D-glucose (dGlc) inhibited culture growth.
Abstract: Carrot (Daucus carota L.) cell suspension cultures grew well when provided with glucose, fructose, sucrose or raffinose. Galactose and melibiose supported less growth unless supplemented with glucose or fructose. In combination with ten different sugar mixtures, 2-deoxy-D-glucose (dGlc) inhibited culture growth. Inhibitory effects of dGlc were more marked with fructose, melibiose, raffinose or mixtures of these sugars in the culture medium. The presence of glucose or galactose reduced the inhibitory effects of dGlc on culture growth. Experiments with radioactive labelled sugars demonstrated that dGLc uptake was greater in the presence of fructose than glucose, and that growth inhibition of dGlc coincided with its uptake. Reduced protein content was also associated with the inhibitory effects of dGlc. Cultured cells contained lower levels of invertase (EC 3.2.1.26) activity during the active phase of culture growth (up to 25 days after subculture) than when growth had peaked and subsequently declined. Acid and alkaline invertase activities were not greatly reduced by exogenous hexoses. Invertase activity was greatest during periods of low protein content in all cultures and was inhibited by dGlc during the latter phases of the culture period. Free intracellular sugars throughout the culture period consisted mainly of glucose and fructose.
TL;DR: Observed fermentative and assimilative differences among the wine isolates confirmed the presence of physiological races of S cerevisiae in Raphia palmwine, and suggest that physiological races in palmwine may influence the wine's organoleptic and aromatic qualities.
Abstract: Using 34 carbon and four nitrogen compounds, and 12 standard yeast identification tests, eight isolates of Saccharomyces cerevisiae Hansen from Raphia Beaur (Palmae) palmwine and other sources were evaluated comparatively for morphological and physiological characteristics. Differences among the isolates were found mainly in their formation of pseudomycelium and blastospores, and in the fermentative utilisation of galactose, maltose, melibiose, raffinose, trehalose and α-methyl-D-galactoside. The wine isolates varied primarily in their assimilatory capabilities for lactic acid and maltose. Observed fermentative and assimilative differences among the wine isolates confirmed the presence of physiological races of S cerevisiae in Raphia palmwine, and suggest that physiological races of S cerevisiae in palmwine may influence the wine's organoleptic and aromatic qualities.
TL;DR: It is demonstrated that the highest α-galactosidase productivity observed in the early stationary phase of growth is not associated with a starvation condition, but it is coupled to a particular growth phase.
Journal Article•
01 Jan 1989
TL;DR: Analysis of S.mutansgafA mutantstrains revealed that they synthesized less a-galactosidase activity inducible byraffinose than wild-type strains, and it is hypothesized that melibiose use by S. mutans requires the interaction of the GTFAenzyme, or another geneproduct under the control of thegifA promoter, withother geneps involved inmelibiose transport orhydrolysis.
Abstract: enzyme. Analysis ofS.mutansgtfA mutants revealed thatthemutantstrains werespecifically impaired intheability touse melibiose asasole carbon source. S.mutansgafA mutantstrains synthesized less a-galactosidase activity inducible byraffinose thanwild-type strains. Melibiose (aninducer inwild-type strains) failed toinduce significant levels ofa-galactosidase inthemutantstrains. We hypothesize thatmelibiose usebyS.mutans requires theinteraction oftheGtfAenzyme, oranother geneproduct underthecontrol ofthegifA promoter, withother geneproduct(s) involved inmelibiose transport orhydrolysis.