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A Slomiany

Publications and source records attributed to A Slomiany.

At least 325 records · Page 18Linked to original sources
PubMed1981

A new method for the isolation of the simple and highly complex glycosphingolipids from animal tissue.

The most widely used methods for the extraction of glycosphingolipids from animal tissues are based on the use of chloroform/methanol mixtures. These methods, although suitable for a great majority of lipids, fail to remove highly complex glycosphingolipids. Reported here is a method for the isolation of the entire population of glycosphingolipids by means of a gradual degradation of tissue components and enrichment in carbohydrate conjugates resistant to alkali and proteases. Fresh gastric mucosa was homogenized and treated with alkali (beta-elimination) and RNAase and DNAase to decrease the viscosity of the homogenate, followed by pronase digestion. Each treatment was completed by exhaustive dialysis against distilled water. The resultant tissue digest was partitioned with chloroform/methanol (2:1) to remove simple glycosphingolipids. The aqueous portion of the system was adjusted to 1.0% with Zwittergent TM- 314 and solubilized for 24 h by mixing. Thus, prepared sample subjected to Bio-Gel P60 column chromatography afforded five fractions. Of these, three were free of protein and contained carbohydrates, fatty acids and sphingosine. Further fractionation on Bio-Gel P 10 and P6 columns followed by thin-layer chromatography afforded homogeneous components with all the characteristics of highly complex glycosphingolipids.

Animals↗
PubMed1981

Characterization of the sulfated monosialosyltriglycosylceramide from bovine gastric mucosa.

A sulfated monosialosyltriglycosylceramide was isolated from the lipid extract of bovine gastric mucosa in a yield of 2.52 microM/kg of wet tissue. The isolation procedure involved extraction of lipids with 0.4 M sodium acetate in methanol/chloroform/water, alkaline methanolysis, column fractionation on DEAE-Sephadex and silicic acid, and thin-layer chromatography. Based on the results of partial acid hydrolysis, sequential degradation with specific glycosidases, periodate oxidation, and methylation analysis of the native and partially degraded compound, the structure of this glycolipid is proposed to be: GalNAc beta 1 leads to 4(SO3H leads to 8Sia alpha 2 leads to 3)Gal beta 1 leads to 4Glc1 leads to 1Cer. The sialic acid of this glycolipid consisted of N-acetylneuraminic acid and N-glycoloylneuraminic acid, with the former being predominant component (71%) of the mixture.

Animals↗
PubMed1980

Isolation and characterization of oligosaccharides from rat colonic mucus glycoprotein.

The structure of carbohydrate units of rat colonic mucus glycoproteins was investigated. Alkaline borohydride reductive cleavage of the glycoprotein resulted in the release of a series of reduced oligosaccharides. Eight of the oligosaccharides (1 to 8), ranging in length from 2 to 12 sugar units, have been purified to homogeneity and their structures determined. Based on the results of immunological assays, analysis of sugar composition, sequential degradation with specific glycosidases, and methylation analyses of the intact and desialyzed oligosaccharides, we propose the following structures for these compounds: (Formula: See text).

Animals↗
PubMed1980

Glycosphingolipids of guinea pig gastric mucosa.

Glycosphingolipids have beenn isolated from guinea pig gastric mucosa and their composition and content determined. The neutral glycospingolipids were found to consist of mono-, di-, tri- and pentaglycosylceramide. The acidic glycosphingolipids wee represented by galactosyl and lactosyl sulfatides, and GM4, GM3 and GD3 gangliosides. None of the analyzed glycolipids contained N-acetylglucosamine and fucose.

Animals↗
PubMed1980

Sulfated trihexosylceramide from gastric mucosa containing N-acetylglucosamine.

A new sulfated glycosphingolipid containing N-acetylglucosamine has been isolated from hog gastric mucosa by extraction with sodium acetate. Based on the results of partial acid hydrolysis, sequential degradation with specific glycosidases, and methylation analysis of the native and desulfated compound, the structure of this glycolipid is proposed to be: SO3H(leads to 6)GlcNAc-(beta 1 leads to 3)Gal(beta 1 leads to 4)Glc(1 leads to 1)Cer(GlcNAc, N-acetylglucosamine; Cer, ceramide).

Acetylglucosamine↗
PubMed1980

The neutral and acidic glyceroglucolipids from gastric mucous barrier of rat-stomach antrum, body and forestomach.

Distribution of glyceroglucolipids in the mucous barrier of rat-stomach antrum, body and forestomach was investigated. Surface mucus lining and preformed intracellular mucus were obtained by perfusion in vivo of the ligated stomach compartments wit saline and 2 M NaCl. Lipids were extracted from dialyzed and lyophilized samples, and separated on DEAE-Sephadex into neutral and acidic fractions. The glyceroglucolipids contained in each fraction were quantified and then separated into individual components by thin-layer chromatography. Significant differences in the concentration of glyceroglucolipids in the separated areas of the stomach were found. The content of glyceroglucolipids in the antral portion of the stomach was five-times greater than that of the forestomach. The level of sulfated glyceroglucolipids was eight-times greater in the antrum as compared to the body and four-times greater as compared to the forestomach. One sulfated glyceroglucolipid was present in antral perfusates, whereas the body and forestomach contained two additional acidic glyceroglucolipids. Based on data of partial acid and alkaline methanolyses, oxidation with periodate and chromium trioxide, and methylation of the native and desulfated compound, the structure of antral glyceroglucolipid is proposed to be: SO3H(leads to 6)Glc(alpha 1 leads to 6)Glc-(alpha 1 leads to 6)Glc(alpha 1 leads to 6)Glc(alpha 1 leads to 3)-1(3)-O-alkyl-2-O-acylglycerol. The neutral glyceroglucolipid fractions from each area of the stomach were similar in composition and only variations in their concentration were observed. The data obtained suggest that the sulfated glyceroglucolipids are involved in the protection of the gastric mucosa of the antrum, since their concentration is greatest in this most acidic portion of the stomach which is also most often exposed to duodenal reflux.

Animals↗
PubMed1980

Complex fucolipids of hog gastric mucosa. Structure of the ceramide eikosahexoside.

The structure of a complex fucolipid from hog gastric mucosa containing twenty sugar residues and exhibiting blood-group (A + H) activity has been investigated. Based on the results of immunological assays, partial acid hydrolysis, sequential degradation with specific exoglycosidases, oxidation with periodate and chromium trioxide, and permethylation analysis, we suggest that the carbohydrate chain of this fucolipid contains four termini. One of the termini bears beta Gal1 leads to 4 beta GlcNAc disaccharide, two bear blood-group A determinant and one bears H determinant. Two of the branches, terminated by beta Gal1 leads to 4 beta GlcNAc and blood-group A determinant, and two terminated by blood-group A and H determinants, are linked through beta Gal1 leads to 4 beta GlcNAc1 leads to 3/6 and beta Gal1 leads to 4 beta GlcNAc1 leads to 4 beta GlcNAc1 leads to 3/6 to the galactose residue adjacent to glucosylceramide core.

ABO Blood-Group System↗
PubMed1979

The neutral glyceroglucolipids of alveolar lavage from rabbit.

Three individual glycolipids have been isolated from the neutral lipid fraction of rabbit alveolar lavage. All three glycolipids contained glucose, glyceryl monoethers and fatty acids, and differed from each other primarily with respect to the number of glucose residues. The structures of these glycolipids were identified by mild alkaline methanolysis, oxidation with periodate and CrO3, and methylation studies, as: Glc(alpha 1 leads to 3)-1,(3)-O-alkyl-2-O-acylglycerol, Glc(alpha 1 leads to 6)Glc(alpha 1 leads to 6)Glc(alpha 1 leads to 6)Glc(alpha 1 lead to 6)Glc(alpha 1 leads to 3)-1,(3)-O-alkyl-2-O-acyglycerol, and Glc(alpha 1 leads to 6)Glc(alpha 1 leads to 6)Glc(alpha 1 leads to 6)Glc(alpha 1 leads to 6)Glc(alpha 1 leads to 6)Glc(alpha 1 leads to 3)-l,(3)-O-alkyl-2-O-acylglycerol.

Animals↗
PubMed1979

Structural studies on the carbohydrate units of armadillo submandibular glycoprotein.

The structure of carbohydrate units of the major glycoprotein fraction of armadillo submandibular gland was investigated. Alkaline borohydride reductive cleavage of the glycoprotein resulted in the release of O-glycosidically linked mono- and disaccharide units. The monosaccharide was identified as N-acetylgalactosaminitol, whereas disaccharide contained of N-acetylneuraminic acid and N-acetylgalactosaminitol. Treatment of the native and desialyzed glycoprotein with alpha-N-acetylgalactosaminidase resulted in the removal of 60% and 96% of N-acetylgalactosamine, respectively. No cleavage of this sugar was affected by the action of beta-N-acetylhexosaminidase. Both N-acetylgalactosamine and N-acetylneuraminic acid were susceptible to oxidation with periodate. Analyses of the partially methylated N-acetylgalactosamine derivatives, obtained from the permethylated native glycoprotein, showed the presence of 3,4,6-tri-O-methyl-N-methylacetamidogalactose and 3,4-di-O-methyl-N-methylacetamidogalactose in a ratio of 1 : 0.4. Only 3,4,6-tri-O-methyl-N-methylacetamidogalactose was found in the hydrolysates of permethylated desialyzed glycoprotein. These results together with our previous data on chemical composition of the glycoprotein suggest that about 30% of the oligosaccharide chains consist of NeuAc alpha 2 leads to 6GalNAc alpha 1 leads to O-Thr(Ser) and 70% of GalNAc alpha leads to O-Thr(Ser).

Animals↗
PubMed1979

Isolation and characterization of a sulfated glyceroglucolipid from alveolar lavage of rabbit.

A major acidic glycolipid of the rabbit alveolar lavage has been isolated and characterized. The isolation procedure involved extraction of lipids, column fractionation on DEAE-Sephadex and silicic acid, and thin-layer chromatography. Chemical analysis of the glycolipid revealed the presence of glucose, fatty acids, glycerol mono-ethers and sulfate. By partial acid and alkaline methanolysis, oxidation with periodate and chromium trioxide, and methylation analysis of the native and desulfated compound, the structure of this glycolipid is proposed to be: SO3H-6Glc alpha 1 leads to 6Glc alpha 1 leads to 6Glc alpha 1 leads to 6Glc alpha 1 leads to 3-1,(3)-O-alkyl-2-0-acylglycerol.

Chromatography, Thin Layer↗
PubMed1978

Structures of the acidic oligosaccharides isolated from rat sublingual glycoprotein.

Alkaline borohydride reductive cleavage of the major glycoprotein fraction of rat sublingual gland resulted in the release of a series of reduced oligosaccharides. Five sialic acid-containing oligosaccharides composed of 9, 10, 12, 13, and 15 sugar residues, respectively, have been purified from the acidic oligosaccharide fraction. The structures of these oligosaccharides, as determined by sequential digestion with specific glycosidases, periodate oxidation and methylation analyses of the native and desialyzed compounds, are proposed to be (formula: see text).

Animals↗
PubMed1978

Blood-group-(A + H) complex fucolipids of hog gastric mucosa.

A new group complex glycosphingolipids exhibiting blood-group-(A + H) activity was isolated from the lipid extract of hog gastric mucosa. Four components of this group have been purified to homogeneity and their structures and immunological properties were studied. The branched structures of glycolipids were identified by partial acid hydrolysis, sequential degradation with specific glycosidases, oxidation with periodate and chromium trioxide, and comparison of the permethylation products of the native and defucosylated compounds. The structures of these fucolipids are proposed to be as follows.

ABO Blood-Group System↗
PubMed1978

Lipid composition of the gastric mucous barrier in the rat.

The lipid composition of the "mucous barrier" of rat stomach was investigated. Cellular mucus of the mucous cells from gastric epithelium and surface mucus from gastric mucosa were obtained by perfusion in vivo of Ghosh-Lai rat stomachs with 2 M NaCl. Lipids extracted from dialyzed and lyophilized 2 M NaCl perfusates and 0.9% NaCl (saline) controls were quantitatively separated into single components by means of two-dimensional thin layer chromatography and compared. Significant differences in the level of cholesterol esters, di- and triglycerides, and glycolipids were found. Three to 4 times greater quantities of cholesterol esters and di- and triglycerides, and 2 to 6 times greater quantities of glycolipids were found in 2 M NaCl perfusates as compared to saline controls. The glycolipid fraction consisted of neutral and acidic glyceroglucolipids and was devoid of glycosphingolipids. The phospholipids constituted the smallest portion of the lipids present in 2 M NaCl and saline perfusates and were 2 times higher in 2 M NaCl. These data indicate that mucous barrier in addition to mucins contains considerable quantities of lipids of which glyceroglucolipids are the most prominent components.

Animals↗