Activity of enzymes catalyzing formation of beta-L-fucosyl phosphate and GDP-beta-L-fucose in amphibian tissues and their application in chemo-enzymic synthesis of GDP-beta-L-fucose.

Amphibian oviduct and liver were shown to contain enzymes that catalyze the formation of GDP-beta-L-fucose from GDP-alpha-D-mannose or L-fucose. The conversion of L-fucose into beta-L-fucopyranosyl phosphate was achieved on a preparative scale using high-activity fucokinase in toad liver extracts. For chemo-enzymic preparation of GDP-beta-L-fucose, a convenient modification for pyrophosphate synthesis through phosphomorpholidate which does not require anhydrous conditions is suggested.     

Physicochemical characteristics of Listeria specific antigen 2

Listeria specific antigen 2 (Ag2) was purified to within 97% of homogeneity, with a high yield, using both gel filtration and polyacrylamide gel electrophoresis. Ag2 is a glycoprotein. Its isoelectric point is about 4.2. As determined by sodium dodecyl sulphate-polyacrylamid gel electrophoresis, its molecular weight in 16710 +/- 450. Ag2 may aggregate easily since it was previously found in gel filtration in a peak corresponding to a molecular weight of 160000. No enzyme activity has been found in Ag2.     

2-Acetamidoglucal,a new metabolite isolated from the urine of a patient with sialuria

A new metabolite, namely 2-acetamidoglucal, has been found in the urine of a patient with sialuria in addition to the metabolites N-acetylneuraminic acid, N-acetylmannosamine, N-acetylglucosamine and N-deoxy-2,3-dehydro-Nacetylneuraminic acid reported earlier. The structure has been identified by mass spectrometry and 360 MHz proton nuclear magnetic resonance spectroscopy and verified by synthesis. All accumulated compounds fit into the metabolic pathway for the biosynthesis of CMP-N-acetylneuraminic acid. Sialuria is discussed in terms of a failure of regulation of UDP-N-acetyl-glucosamine 2-epimerase.