Showing papers on "Melibiose published in 1971"
TL;DR: In cell-free extracts p -nitrophenyl- α -galactoside hydrolisis was observed only at high protein concentrations and the activity decreased exponentially with the square of the dilution, and its purification has not been achieved due to the instability of the enzyme.
60 citations
TL;DR: A clear-cut correlation between survival, metabolism, and flight potential on different carbohydrates has been presented for A. taeniorhynchus females and suggested that there is some species specificity in the utilization of different carbohydrates by mosquitoes.
48 citations
TL;DR: FEM medium was used to recover four marine type C isolates from inshore sediments collected along the Atlantic, the Gulf of Mexico, and the Pacific coasts of the United States and various cultural and biochemical characteristics of the marine and terrestrial strains showed similar characteristics.
Abstract: Terrestrial strains of Clostridium botulinum type C, designated 468 and 571, were used to screen various media for growth and sporulation at 30 C. Of the various formulations tested, only egg meat medium fortified with 1% additions of yeast extract, ammonium sulfate, and glucose (FEM medium) gave good growth and satisfactory sporulation. FEM medium was used to recover four marine type C isolates from inshore sediments collected along the Atlantic, the Gulf of Mexico, and the Pacific coasts of the United States. The isolation techniques involved repeated transfer of cultures showing type C toxin in FEM medium and purification by a deep tube method. The medium used for purification was beef infusion-agar supplemented with 0.14% sodium bicarbonate and 0.1% l-cysteine hydrochloride. l-Cysteine was adopted in preference to sodium thioglycolate, because some lots of the latter were definitely inhibitory for growth. The addition of bicarbonate markedly increased viable spore counts of both the marine and terrestrial strains. Various cultural and biochemical characteristics of the marine and the terrestrial strains were compared. With the exception of some variations in their fermentation patterns, both groups showed similar characteristics. Of 23 fermentable compounds tested, the terrestrial strains attacked only glucose and mannose. The marine strains fermented glucose, mannose, galactose, and ribose actively; dextrin, inositol, maltose, and melibiose were weakly fermented.
38 citations
TL;DR: The pH of the culture filtrate usually increased slowly during the growth period when the fungus grew poorly and no sclerotia were formed, but a combination of glucose plus trehalose or polyols resulted in increased growth and the formation of sclerotsia.
Abstract: Sclerotinia sclerotiorum (Lib.) D By. was grown in stationary liquid mineral-salts medium, pH 4.3, containing various carbon sources and the weight of mycelia and sclerotia was determined at regular intervals. When grown on various glucose concentrations (0–24 g of C/l), more sclerotia were produced at 8–12 g of C/l. Sclerotia were not usually formed in shake cultures. The ability of the fungus to use other carbon sources for growth and sclerotium formation was tested at 12 g of C/l in the stationary mineral-salts medium. The highest weights of mycelia and sclerotia occurred with raffinose, sucrose, maltose, lactose, d-mannose, d-glucose, d-fructose or l-arabinose. Good growth but decreased sclerotium production were found on cellobiose and d-xylose. Reduced or poor growth, a long lag period and few or no sclerotia occurred on trehalose, melibiose, l-sorbose, l-rhamnose, d-ribose, d-arabinose, l-xylose or 8 polyols. No growth was observed with erythritol or i-inositol. A combination of glucose plus trehalose or polyols resulted in increased growth and the formation of sclerotia. Organic acids supported little or no growth and no sclerotia were produced. Generally culture filtrates which supported growth and formation of sclerotia became acid (about pH 3.5). The pH of the culture filtrate usually increased slowly during the growth period when the fungus grew poorly and no sclerotia were formed. The alcoholsoluble sugars and polyols present in culture filtrates, mycelia and sclerotia were determined by paper and thin-layer chromatography. Regardless of the carbon source, mannitol was usually present in culture filtrates. The occurrence of other compounds in the filtrates depended on the carbon source. Trehalose, mannitol and usually small quantities of glucose or fructose were present in mycelia and sclerotia from all carbon sources. Galactitol or pentitols occurred in mycelia and sclerotia when the fungus grew on galactose and oligosaccharides containing galactose or the corresponding pentose, sugars. Acid hydrolyzates of the alcohol-insoluble fraction of mycelia or sclerotia contained glucose, smaller amounts of galactose and mannose and traces of ribose and rhamnose.
27 citations
TL;DR: The results corroborate the α-galactosidase deficiency reported in Fabry's disease and establish that the terminal galactosyl residue of the trihexosyl ceramide stored in this condition has an α-configuration.
22 citations
TL;DR: D-Glucose in dilute aqueous solution in the presence of orthophosphate and cyanogen is phosphorylated to produce α-D-glucopyranose 1-phosphate, which is suggested as a model for the prebiotic synthesis of sugar phosphates.
Abstract: D-Glucose in dilute aqueous solution (pH 6·7–8·8) in the presence of orthophosphate and cyanogen is phosphorylated to produce α-D-glucopyranose 1-phosphate (yield 8–20%), β-D-glucopyranose 1-phosphate (2–5%), and a phosphorylated disaccharide (3–34%). The products were identified by paper chromatography and electrophoresis and by hydrolytic studies. The first-order rate constants for hydrolysis of α- and β-glucopyranose 1-phosphate in 1·16M-perchloric acid at 25° are 4·14 × 10–5 s–1, respectively. α-D-Glucose 1-phosphate (Cori ester) was further identified by a highly specific enzymic assay.The cyanogen-induced phosphorylation is a general reaction for reducing sugars; non-reducing sugars are inert. Thus, phosphorylation is also successful with the monosaccharides D-arabinose, D-ribose, D-xylose, D-galactose, D-mannose, D-fructose, D-glucosamine, N-aceyl-D-glucosamine, and with the disaccharides maltose, melibiose, cellobiose, and lactose, but fails with glycerol, sucrose, and trehalose.In the case of D-arabinose, the products are D-arabinopyranose 1-phosphate and D-arabinofuranose 1-phosphate, obtained in 3–5% and 0·5–1·5% yield, respectively.Evidence for the mechanism of cyanogen-induced phosphorylation was obtained by studying the hydrolysis of cyanogen and orthophosphate in H218O. The observed rapid uptake of 18O into the orthophosphate, without isotopic dilution of the water, indicates initial formation of a cyanogen–phosphate adduct [CN–CN + HPO42–→ NC–C(NH)–O·PO32–] which then undergoes hydrolysis to produce 18O-labelled orthophosphate [NC–C-(NH)–O–PO32–+ H218O → NC·CO·NH2+18O·PO32–]. With an excess of cyanogen, the orthophosphate undergoes further cycles of 18O uptake from the water. In the presence of reducing sugars, the intermediate cyanogen–phosphate adduct acts as a phosphorylating agent, attacking the glycosidic hydroxy-groups to produce glycosyl phosphates. Cyanogen-promoted phosphorylation is suggested as a model for the prebiotic synthesis of sugar phosphates.
17 citations
TL;DR: Two phenotypic classes of mutants not able to utilize melibiose as a carbon source are isolated, one class, Car(-), is deficient in the phosphotransferase system, and the other, Mel, lacks either alpha-galactosidase, galactoside permease, or both functions.
Abstract: I identified two enzyme activities, alpha-galactosidase and a galactoside permease, required for melibiose metabolism by Salmonella typhimurium. These activities are very low under normal growth conditions, but their production can be induced by melibiose and gratuitously by melibiitol. Melibiose induction is severely inhibited by glucose, but the glucose effect can be countered by 3', 5' cyclic adenosine monophosphate. I isolated two phenotypic classes of mutants not able to utilize melibiose as a carbon source. One class, Car(-), is deficient in the phosphotransferase system. The other, Mel, lacks either alpha-galactosidase, galactoside permease, or both functions.
17 citations
TL;DR: The CD-spectra of gentiobiose (18), isomaltose (19) and melibiose (20) molybdate solutions show at 275 nm a positive and at 242 nm a negative Cotton Effect as mentioned in this paper.
Abstract: Die CD-Spektren von Gentiobiose- (18), Isomaltose- (19) und Melibiose- (20) Molybdat- Losungen zeigen alle bei 275 mν einen negativen Cotton-Effekt, wahrend l- und 4-O-Pyranosyl-Pyranosen keinen Effekt aufweisen. Damit konen also 6-O-Pyranosyl-pyranosen mit einer Messung erkannt werden.
Investigations of Di- and Trisaccharides with Circular Dichroism
The CD-spectra of gentiobiose (18), isomaltose (19) and melibiose (20) molybdate solutions show at 275 nm a positive and at 242 nm a negative Cotton Effect in contrast to molybdate solutions of l- and 4-O-pyranosylpyranoses. By this method therefore 6-O-pyranosylpyranoses may be determined by one measurement.
6 citations
TL;DR: The riboflavinyl glucoside (5'- D -riboflavin-α- D -glucopyranoside) is obtained with the acetone-dried powder of rat liver and various kinds of rib oflavin glycosides, which are readily soluble in cold water, sparingly soluble in ethanol, but insoluble in ether.
Abstract: Publisher Summary The riboflavinyl glucoside (5'- D -riboflavin-α- D -glucopyranoside) is obtained with the acetone-dried powder of rat liver and various kinds of riboflavin glycosides: riboflavinyl galactoside, riboflavinyl fructoside, and riboflavin oligosaccharides are easily formed from riboflavin and saccharide with Aspergillus oryzae or Taka-Diastase. Lactose and melibiose serve as galactosyl donors for riboflavinyl galaetosides. Sucrose serves both as fructosyl and glucosyl donor for riboflavinyl fructoside and riboflavinyl glucoside. All the glycosides are readily soluble in cold water, sparingly soluble in ethanol, but insoluble in ether. The melting point is 248°C–249°C for riboflavinyl glucoside and its crystals of turn brown and decomposes. The ratio of absorbancy at 375 to 450 nm is 0.85 for riboflavinyl glucoside. The growth of Aspergillus oryzae , Taka-Diastase powder, enzyme solution from cotyledons, and enzymatic synthesis are reviewed. The purification procedure involves the Crammer method with some modification.
4 citations
TL;DR: Two isolates of Entophlyctis confervae-glomeratae (Cienkowski) Sparrow grew at 10–25C and in the range pH 6–9.5 and used glucose, fructose, trehalose, glycerol, sucrose, cellobiose, maltose, and starch but not lactose, xylose, ribose, sorbitol, raffinose, rhamnose, melibiose, N-acetyl-
Abstract: Two isolates of Entophlyctis confervae-glomeratae (Cienkowski) Sparrow grew at 10–25C and in the range pH 6–9 Both isolates used ammonium, nitrate, and nitrite nitrogen They used glucose, fructose, trehalose, glycerol, sucrose, cellobiose, maltose, and starch but not lactose, xylose, ribose, sorbitol, raffinose, rhamnose, melibiose, N-acetyl-D-glucosamine, or cellulose
2 citations
TL;DR: The blood group B substance-degrading activity of Streptomyces 9917S2 is induced by galactosides as α-galactosidase activity is, and this enzyme preparation cleaves α-(1→3)- and α-( 1→6)-galactOSidic linkages.
Abstract: The blood group B substance-degrading activity of Streptomyces 9917S2 is induced by galactosides as α-galactosidase activity is. Purification of the α-galactosidase was attempted by chromatography on DEAE-Sephadex and Sephadex. The purified preparation was shown to be free from α- and β-glucosidases, β-galactosidase, α- and β-glucosaminidases, and α- and β-galactosaminidases activities. The blood group B substance-degrading activity was present only in this fraction. This enzyme preparation cleaves α-(1→3)- and α-(1→6)-galactosidic linkages. The activity is inhibited by d-galactose, melibiose, and raffinose and also by l-arabinose and d-xylose.
TL;DR: The CD-spectra of gentiobiose (18), isomaltose (19) and melibiose (20) molybdate solutions show at 275 nm a positive and at 242 nm a negative Cotton Effect as mentioned in this paper.
Abstract: Die CD-Spektren von Gentiobiose- (18), Isomaltose- (19) und Melibiose- (20) Molybdat- Losungen zeigen alle bei 275 mν einen negativen Cotton-Effekt, wahrend l- und 4-O-Pyranosyl-Pyranosen keinen Effekt aufweisen. Damit konen also 6-O-Pyranosyl-pyranosen mit einer Messung erkannt werden.
Investigations of Di- and Trisaccharides with Circular Dichroism
The CD-spectra of gentiobiose (18), isomaltose (19) and melibiose (20) molybdate solutions show at 275 nm a positive and at 242 nm a negative Cotton Effect in contrast to molybdate solutions of l- and 4-O-pyranosylpyranoses. By this method therefore 6-O-pyranosylpyranoses may be determined by one measurement.