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V L Murty

Publications and source records attributed to V L Murty.

87 records · Page 5Linked to original sources
PubMed1983

Lipids of supragingival calculus.

The matrix of supragingival calculus constitutes 15.7% of the calculus dry weight and contains 54.9% protein and 10.2% lipids. Of the total lipids, 61.8% are represented by neutral lipids, 28% by glycolipids, and 10.2% by phospholipids. The neutral lipids exhibit a high content of free fatty acids (63.9%) and triglycerides (15.8%). The glycolipids are comprised of simple glycosphingolipids (17.2%), mainly lactosyl- and glucosylceramides, and of neutral and sulfated glyceroglucolipids (82.8%). The phospholipids contain large quantities of phosphatidylethanolamine (34.2%) and diphosphatidylglycerol (25.5%). Comparison with salivary and submandibular stone lipids indicates that both saliva and bacteria contribute to the lipid content of supragingival calculus.

Chromatography, Gas↗
PubMed1983

Lipid composition of human parotid salivary gland stones.

The parotid gland stone matrix constitutes 20.2% of the stone dry weight and contains 8.5% of lipids. Of the total lipids, 74% are represented by neutral lipids, 17% by glycolipids, and 9% by phospholipids. The neutral lipids exhibit a high content of free fatty acids (52.7%) and cholesteryl esters (31.1%). The glycolipids are composed of simple glycosphingolipids (7.1%), and of neutral and sulfated glyceroglucolipids (92.9%). Phosphatidylethanolamine and diphosphatidylglycerol are the principal constituents of the phospholipid fraction.

Chromatography, Gas↗
PubMed1982

Lipid composition of tracheobronchial secretions from normal individuals and patients with cystic fibrosis.

The lipid composition of tracheobronchial secretions from normal individuals and patients with cystic fibrosis was investigated. Lipids were extracted from he dialyzed and lyophilized samples, and fractionated on silicic acid columns into neutral lipids, glycolipids and phospholipids. The lipids contained each fraction were separated into individual components by thin-layer chromatography and quantified. The secretions of patients with cystic fibrosis and were found to contain about 30% more lipids than that of normal individuals and exhibited elevated levels of cholesterol, phospholipids and glycosphingolipids. The level of free fatty acids and glyceroglucolipids was higher in the normal secretions. The phospholipids of cystic fibrosis secretions exhibited higher content of sphingomyelin and phosphatidylserine, while the normal samples contained more lysophosphatidylcholine. The glycosphingolipids of both types of samples consisted mainly of glucosyl- and lactosylceramides. The major glyceroglucolipid of the normal tracheobronchial secretions was tetraglucosyl glyceroglucolipid, whereas hexa-and octaglucosyl glyceroglucolipids were the predominant compounds of the cystic fibrosis secretions.

Bronchi↗
PubMed1982

Lipid composition of human parotid and submandibular saliva from caries-resistant and caries-susceptible adults.

The lipid content and composition of parotid and submandibular saliva from caries-resistant (DMFS of 0) and caries-susceptible (DMFS greater than 15) adults was investigated. Lipids were extracted from dialysed and lyophilized saliva, collected from 10 subjects in each group, and fractionated into neutral lipids, glycolipids and phospholipids. The lipids in each fraction were separated into individual components by thin-layer chromatography and quantitated. The parotid and submandibular saliva of caries-resistant subjects contained 37 and 35 per cent fewer lipids/100 ml of saliva than that of the caries-susceptible group, and had less (p less than 0.001) neutral lipids and phospholipids. The neutral lipids of caries-resistant saliva contained (mg/100 ml of saliva) considerably (p less than 0.001) fewer free fatty acids, triglycerides and cholesterol esters. The glycolipids consisted exclusively of glyceroglucolipids and their content was similar in both groups. The content of phospholipids in the salivas of the caries-resistant was 25 and 33 per cent lower than that of the caries-susceptible. The data suggest a relationship between the level of lipids in salivary secretions and resistance to caries.

Adult↗
PubMed1982

Lipid composition of the matrix of human submandibular salivary gland stones.

The lyophilized stone matrix, prepared by exhaustive dialysis of pulverized stones against 10 per cent EDTA and water, yielded 9.6 +/- 0.9 mg per cent of lipids. Following fractionation of the lipid extract on silicic acid columns, 57 per cent of lipids were found in the neutral lipid fraction, 40 per cent in the glycolipid fraction and 3 per cent in the phospholipid fraction. Of the total neutral lipids, 77.3 per cent were represented by free fatty acids, 14.7 per cent by cholesterol, 4.1 per cent by triglycerides and 3.2 per cent by cholesterol esters. The glycolipid fraction was comprised of simple glycosphingolipids (11.3 per cent), mainly lactosyl- and glucosylceramides, and of neutral and sulphated glyceroglucolipids (88.7 per cent). The sulphated glyceroglucolipids consisted of tri- and tetraglucosyl glyceroglucolipids, whereas hexa- and octaglucosyl glyceroglucolipids were the predominant constituents of the neutral glyceroglucolipid fraction. The phospholipids exhibited a high content of sphingomyelin (22.3 per cent), phosphatidylcholine (12.1 per cent), phosphatidylethanolamine (11.4 per cent), phosphatidylserine (10.5 per cent) and lysophosphatidylcholine (13.3 per cent). The major fatty acids of the neutral lipid fraction were hexadecanoate, octadecanoate and octadecenoate. The glycolipids contained large quantities of hexadecanoate and tetracosanoate, while the hexadecanoate, octadecanoate and tetracosanoate were the principal fatty acids of the phospholipid fraction.

Adult↗
PubMed1982

Lipid composition of submandibular saliva from normal and cystic fibrosis individuals.

The submandibular saliva of patients with cystic fibrosis was found to contain about 66% more lipids/100 ml of saliva than that of normal individuals and exhibited elevated levels of neutral lipids, phospholipids, and glycolipids. No significant differences were noted in the proportions of individual neutral lipid and phospholipid components present in both types of samples. The glycolipids of normal saliva consisted entirely of glyceroglucolipids, whereas those of cystic fibrosis saliva, in addition to glyceroglucolipids, also contained small amounts of glycosphingolipids. These quantitative and qualitative differences may affect the physicochemical properties of the secretion.

Adolescent↗
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↗
PubMed1978

Rat-colonic, mucus glycoprotein.

A glycoprotein was isolated from rat-colonic mucosa. Analytical ultracentrifugation studies showed the glycoprotein to be homogeneous, having an apparent molecular weight of 9.0 X 10(5); no subunits could be detected in the presence of sodium dodecyl sulfate. It contained 14% of protein and 86% of carbohydrate. The principal sugars in the glycoprotein were galactose, fucose, sialic acid, 2-acetamido-2-deoxygalactose, and 2-acetamido-2-deoxyglucose. A small proportion of mannose was also present. The glycoprotein, apart from the usual carbohydrate constituents present in mucus glycoproteins, contained sulfate, but no uronic acid. High amounts of serine and threonine, and low contents of aromatic and traces of sulfur-containing amino acids, reflect a similarity of this glycoprotein to other mammalian mucus glycoproteins; it differs, however, by its high proportions of Asx + Glx (26 mol.%). Cleavage studies with alkaline borohydride indicated O-glycosidic linkages between N-acetylhexosamine and serine, and threonine, of the peptide core in the glycoprotein. Only about one third of the serine and threonine was linked to the carbohydrate side-chains, which averaged about 22 units in length and were apparently branched.

Amino Acids↗
PubMed1977

Quantitation of the beta-elimination reaction as used on glycoproteins.

The carbohydrate side chains of mucus-type glycoproteins are O-glycosidic bonds between N-acetylgalactosamine to the hydroxyl groups of serine and threonine in the protein core. The alkaline catalyzed beta-elimination reaction, in the presence of sodium borohydride, is used for determining the number of side chains. The present paper presents a study of the quantitativeness of the alkaline borohydride procedure, using four parameters: the loss of seryl and threonyl residues, the formation of alanine and 2-aminobutanoic acid; the decrease in N-acetylhexosamine and the recovery of the amino sugar alcohols. Bovine, ovine and porcine submandibular glycoproteins were studied. Evidence is presented for the existence of N-acetylglucosamine involvement in O-glycosidic linkages to serine and threonine. Results for the relative rates of beta-elimination indicate that serine-linked glycosides are released more rapidly than threonine-linked glycosides.

Alanine↗
PubMedDate not supplied

Effect of bile acids on the glycoprotein constituent of gastric mucus.

The effect of bile acids on the glycoprotein constituent of gastric mucus was investigated. Ghosh-Lai rat stomachs were instilled in vivo for 1 h with buffered saline (control) followed by various bile acids in saline at pH 2.0-7.0. Following quantitative recovery, the instillates were used for the isolation of mucus glycoprotein. The results of analyses revealed that while taurocholic acid exerted essentially identical depletory effects throughout the entire pH range tested, the cholic acid had little depletory effect on the mucus below pH 5.0, and glycocholic acid below pH 4.0. The extent of mucus glycoprotein depletion by bile acids under optimal pH conditions was clearly dependent upon the bile acid concentration as well as its type. The maximum depletory effect with the lowest concentration of bile acid was achieved with taurocholate followed by glycocholate and cholate. Comparison of the depletory effects of mono-, di-, and trihydroxy conjugated and unconjugated bile acids revealed that, within each group, the highest degree of mucus glycoprotein depletion occurred with taurine conjugates. The number of hydroxyl groups on the bile acid molecule appears to exert a less evident effect on the depletory capacity. The results suggest that the in vivo depletion of gastric mucus of its glycoprotein constituent by bile acids depends on the pH of luminal exposure and on the bile acid composition.

Animals↗