5 -pyrophosphate oviducts

In addition to the esters of uridine 5 -pyrophosphate with monosaccharide sulfates, hen oviduct contains corresponding esters with two saccharides. The first known member of this series was a unique derivative 41, in which the monosaccharide residues are linked... 

A disaccharide derivative (42) of more conventional structure has also been isolated from hen oviduct.177 Its structure was confirmed by its conversion into L-fucose and uridine 5 -(2-acetamido-2-deoxy-a-D-glucopyranosyl pyrophosphate) after treatment with a-L-fucosi-dase. Mild, acidic hydrolysis of the ester 42 produces a disaccharide whose structure was confirmed by periodate oxidation. Human milk and colostrum,178 or milk and colostrum of pig,128 are also sources of... 

From hen oviduct, enzymes have been isolated and purified that catalyze sulfation of glycosyl esters of nucleoside 5-pyrophosphates by the action of 3 -0-phosphono-5 -adenylyl hydrogen sulfate.448-449... 

A uridine pyrophosphate derivative of Ai -acetyl-n-glucosamine which contains an extra phosphate group has been isolated from a hot-water extract of hen oviducts. Uridine 5-phosphate and uridine 5-pyrophosphate have been recovered from acid hydrolyzates of this compound. A diphosphate ester of A-acetyl-n-glucosamine can also be obtained from acid hydrolyzates of this uridine compound. Because of the catalytic activity of phospho-A -acetyl-n-glucosamine mutase toward it, it is probably AT-ace-tyl-D-glucosamine 1,6-diphosphate. 

Dolichol phosphate, which is a crucial intermediate, has been shown to be synthesised in a variety of tissues and subcellular fractions, of which mitochondrial outer membranes are especially active. These are also a major store of dolichol. The synthesis can start from isopentenyl pyrophosphate or its precursor, mevalonic acid (see the reviews of Beytia and Porter, 1976 Daleo and Pont-Lezica, 1977 Daleo etaiy 1977). In one case the product was the a-unsaturated polyprenol phosphate (dehydrodolichol phosphate), which suggests that a-saturation may occur after phosphorylation, at least in tissues such as hen oviduct (Grange and Adair, 1977 Adair and Keller, 1982). 

The existence of mannosylated saccharides linked to dolichol via a pyrophosphate was already well established. Studies by Behrens etal. (1973) had shown that rat liver microsomes could catalyse the synthesis of various lipid-linked oUgosaccharides from GDP mannose and dolichol phosphate, among which were some that were soluble in chloroform-methanol-water (1 1 0.3, v/v). These were more polar than dolichol monophosphate derivatives and could be bound to DEAE-cellulose in the presence of the organic solvent. In an ammonium formate gradient (also in the organic solvent) these polyprenyl saccharides eluted at the position of dolichol pyrophosphate derivatives. Waechter et al (1973) independently showed that a similar class of compounds was produced from GDP-[ C]maimose in the presence of microsomes from hen oviduct and that the labelled products... 

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