Partial characterization of glyceroglucolipids from human saliva

Identification and isolation of Lewis blood group antigens from human saliva using monoclonal antibodies

Solid-phase radioimmunoassay, polyacrylamide gel electrophoresis and thin-layer chromatography were used to compare, identify, and characterize the Lewis antigens from human salivas, using monoclonal antibodies directed to the Lea and Leb determinants. Sialylated Lea glycolipid was detected in saliva from individuals with Le(a+ b+) and Le(a+ b-) phenotypes. Immunoaffinity chromatography of the saliva from individuals with different phenotypes revealed a glycoprotein of molecular weight greater than 200 kD bearing the Lewis antigenic determinants.

Synthesis of glycolipids

The chemical syntheses of naturally occurring glycolipids derived from sphingosine bases and glycerol derivatives, and the syntheses of polyisoprenoid lipid intermediates and other miscellaneous glycolipids recorded up to the end of 1977 are reviewed.

ABH-blood-group antigens and glycolipids of human saliva

The nature of ABH-blood-group antigens in saliva was investigated. Human saliva was examined serologically for ABH-blood-group activity in its native form and after various treatments. The activity of the native form persisted in the delipidated samples, but was entirely lost after alkaline degradation. The lipid portion of saliva was completely inactive in the ABH hemagglutination inhibition system. The same results were obtained when purified glycolipid fraction of saliva was used instead of whole lipid extract. Neither alkaline treatment nor excessive amounts of salivary lipids effected antigenic activity of A-active glycosphingolipids of hog gastric mucosa admixed to saliva samples before alkaline degradation and/or in presence of large amounts of salivary lipids. The isolated glycolipid fractions contained at least eight glycolipids, each of which was composed of glucose, glyceryl ethers and fatty acids and differed from others with respect to number of glucose residues. Sphingosine and sugar residues involved in formation of ABH antigenic determinants were not detected. These findings together with data on stomach secretion [1,2] led us to the conclusion that ABH-blood-group antigens of saliva are exclusively of glycoprotein nature.

Glyceroglucolipids of the human saliva

Seven individual glycolipids (I--VII) have been isolated from the lipid extract of human saliva. All glycolipids contained glucose, glyceryl ethers and fatty acids, and differed from each other primarily with respect to the number of glucose residues. In addition, glycolipid V contained also the sulfate ester group. The structures of these glycolipids were identified by partial acid and alkaline hydrolysis, oxidation with periodate and chromium trioxide and methylation studies, as: Glc(alpha1 leads to 3)-diglyceride (glycolipid I), Glc(alpha1 leads to 6)Glc(alpha1 leads to 3)-diglyceride (glycolipids II and III), Glc(alpha1 leads to 6)Glc(alpha1 leads to 6)Glc(alpha1 leads to 3)-diglyceride (glycolipid IV), SO3H-6Glc(alpha1 leads to 6)Glc(alpha1 leads to 3)-diglyceride (glycolipid V), Glc(alpha1 leads to 6)Glc(alpha1 leads to 6)Glc(alpha1 leads to 6)Glc(alpha1 leads to 6)Glc(alpha1 leads to 3)-diglyceride (glycolipid VI) and Glc(alpha1 leads to 6)Glc(alpha1 leads to 6)Glc(alpha1 leads to 6)Glc(alpha1 leads to 6)Glc(alpha1 leads to 6)Glc(alpha1 lead to 6)Glc(alpha1 leads to 6)Glc(alpha1 leads to 3)-diglyceride (glycolipid VII). Diglyceride portion of these compounds consists of 1-O-alkyl-2-O-acyl-glycerol with the docosanoate and glyceryl-monodocosyl being the predominant acyl and alkyl components.