Dolichyl diphosphate

This enzyme s activity was found in the membrane fraction of yeast cells (Shabalin et al., 1979, 1985 Naumov et al, 1985 Kulaev et al, 1987 Shabalin and Kulaev, 1989), where PolyP synthesis using /3-phosphate groups of dolichyl diphosphate (Figure 6.3) took place ... 

The enzyme was solubilized from the membrane fraction using Triton X-100 (Shabalin and Kulaev, 1989). The specific activity of the solubilized preparation was 20 times higher than that in protoplast lysate. The dolichyl-diphosphate PolyP phosphotransferase activities of the membrane preparation and solubilized fraction were etal-dependent and exhibited the maximum activity in the presence of Mg2+ or Ca2+. The same membrane fraction posessed... 

Figure 6.4 Two possible pathways for dolichyl diphosphate dephosphorylation in yeast cells Dol-PP, dolichyl diphosphate Dol-P, dolichyl phosphate.

Figure 6.5 The tentative coupling of PolyP and mannan biosynthesis in yeast Dol-PP, dolichyl diphosphate Dol-P, dolichyl phosphate GDPMan, GDPmannose Dol-PP-Man, dolichyl diphosphate mannose (Man) , mannan, where n is the number of mannose residues.

The transformation of D-glucose by a Candida species has been followed catabolically and anabolically. Maximal incorporation into D-glucan and D-mannan is only achieved at a critical concentration of D-glucose. Dolichyl monophosphate-D-mannose is not an intermediate in the synthesis of the outer chains of the D-mannan-protein of Saccharomyces cerevisiae and dolichyl diphosphate oligosaccharides are synthesized by different D-mannosyl-transf erases. ... 

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