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A J Parodi

Publications and source records attributed to A J Parodi.

86 records · Page 5Linked to original sources
PubMed1972

The role of polyprenol-bound saccharides as intermediates in glycoprotein synthesis in liver.

It has been reported that liver microsomes catalyze the transfer of glucose from uridine diphosphate glucose to dolichol monophosphate so as to produce dolichol monophosphate glucose. Dolichol is a polyprenol containing about 20 isoprene units. The glucosyl residue of dolichol monophosphate glucose is transferred to an endogenous acceptor on further incubation with liver microsomes. The glucosylated endogenous acceptor appears to be an oligosaccharide of about 20 monosaccharide units bound to dolichol through a phosphate or pyrophosphate bridge. In this paper it is reported that liver microsomes catalyze the transfer of the oligosaccharide from the glucosylated endogenous acceptor to an endogenous protein. This transfer reaction requires the presence of bivalent cations, manganese being more effective than magnesium. The presence of deoxycholate is also required. Besides the glycoprotein, several water-soluble products are also formed. Preliminary evidence indicates that they are glucose, iligosaccharides of different size, and possibly oligosaccharides bound to amino acids.

Animals↗
PubMed1971

Glucose transfer from dolichol monophosphate glucose: the product formed with endogenous microsomal acceptor.

The product formed by incubation of dolichol monophosphate glucose with liver microsomes was studied. It is insoluble in most solvents, but is soluble in a chloroform-methanol mixture with a high content of water. Treatment with ammonia gave rise to the formation of a water soluble, negatively charged compound of molecular weight 3550. The negative charge could be removed by treatment with phosphatase. Acid hydrolysis of the original compound led to the liberation of an uncharged, water-soluble compound (molecular weight 3550). Acetolysis of the latter gave rise to the formation of a series of products, which appeared to be oligosaccharides when chromatographed on paper or silica plates. The original substance behaved like a polyprenol pyrophosphate when chromatographed on DEAE-cellulose. Molecular weight measurements of the deoxycholate inclusion compound gave a value of 14,300, while dolichol monophosphate glucose under the same conditions gave 11,300. It is tentatively suggested that the compound is dolichol joined through a phosphate or pyrophosphate bridge to an oligosaccharide containing about 20 monosaccharide residues.

Alcohols↗
PubMedDate not supplied

Recent advances in the study of membrane bound saccharides.

The review discusses with the biosynthesis, the changes upon cell density or transformation, the external exposure and the physiological functions of the saccharide moieties of membrane bound sphingoglycolipids and glycoproteins. The structure of biological membranes and some cellular recognition functions tentatively ascribed to membrane bound glycosyl transferases are also reviewed.

Cell Adhesion↗