Calf pancreas microsomes incorporated radioactive mannose from GDP-D-[14C]mannose into products precipitated by 6% trichloroacetic acid-O.5 % phosphotungstic acid. This incorporation was maximally stimulated by 10 mM Mn2+ ions and showed a broad pH optimum of 6.0 to 6.7 in ‘I ris-maleate buffer. Between 70 and 90% of the radioactivity was found in products soluble in chloroform-methanol (2 : 1,...

1. The phosphomannan of Saccharomyces cerevisiae was released by Pronase digestion of cell walls and isolated by chromatography on DEAE-cellulose or by precipitation with borate-Cetavlon solutions. Mannose and phosphorus were present in the molar ratio 18:1 and the phosphate groups were in the diester form. 2. Hydrolysis with acid gave mannose 6-phosphate. Under mild acid conditions (autohydrol...

Herein we present an analysis of the chemical function of a recombinant bifunctional phosphomannose isomerase/GDP-mannose pyrophosphorylase (manC) from Pyrococcus furiosus DSM 3638 and its use in the synthesis of guanidinediphospho-hexoses and a range of nucleotidediphospho-mannoses. This enzyme is unusually promiscuous in both its nucleotide triphosphate (NTP) and sugar-1-phosphate acceptance....

1. A lactating rabbit mammary-gland microsomal system catalysed the incorporation of mannose from GDP-[U-14C]mannose into three endogenous acceptors, (i) polyprenyl phosphate mannose, (ii) lipid-linked oligosaccharide and (iii) protein. 2. Synthesis of polyprenyl phosphate mannose was stimulated by addition of dolichol phosphate to the incubation medium and was reversed by addition of GDP. The ...

In fibroblasts from five patients with carbohydrate-deficient glycoprotein syndrome type 1, the incorporation of [2-3H] mannose into mannose phosphates, GDP-mannose, GDP-fucose, dolichol-P-mannose, lipid-linked oligosaccharides, and glycoprotein fraction was determined. We observed a 3- to 5-fold reduction of incorporation of radioactivity into mannose 1-phosphate, GDP-mannose, GDP-fucose, doli...

Normal and malignant lymphocytes can migrate from the bloodstream into lymph nodes and Peyer's patches. This process helps distribute normal lymphocytes throughout the lymphoid system and may provide a portal of entry for circulating malignant cells. An adhesive interaction between lymphocytes and the endothelium of postcapillary venules is the first step in the migratory process. We have recen...

The interaction of the bovine cation-independent mannose 6-phosphate receptor with a variety of phosphorylated ligands has been studied using equilibrium dialysis and immobilized receptor to measure ligand binding. The dissociation constants for mannose 6-phosphate, pentamannose phosphate, bovine testes beta-galactosidase, and a high mannose oligosaccharide with two phosphomonoesters were 7 X 1...

The mannose 6-phosphate (Man-6-P) lysosomal targeting signal on acid hydrolases is synthesized by the sequential action of uridine 5'-diphosphate-N-acetylglucosamine: lysosomal enzyme N-acetylglucosamine-1-phosphotransferase (GlcNAc-1-phosphotransferase) and GlcNAc-1-phosphodiester alpha-N-acetylglucosaminidase ("uncovering enzyme" or UCE). Mutations in the two genes that encode GlcNAc-1-phosph...

1. The transfer of mannose from GDP-(U-14-C)mannose into endogenous acceptors of bovine adrenal medullla and rat parotid was studied. The rapidly labelled product, a glycolipid, was partially purified and characterized. 2. It was stable to mild alkaline hydrolysis but yielded (14-C)mannose on mild acid hydrolysis. It co-chromatographed with mannosyl phosphoryl dolichol in four t.l.c. systems an...