Conversion of dolichyl pyrophosphate N,N'-diacetylchitobiose to lipid-tri- to heptasaccharides by liver microsomes from hibernating ground squirrels (Citellus citellus L.).
Incubation of liver microsomes from hibernating ground squirrel with GDP-[14C]mannose and exogenous dolichyl phosphate resulted in the synthesis of dolichyl phosphate [14C]mannose. The mannosyltransferase activity was about 3-fold higher in microsomes from hibernating ground squirrels than in those from active animals. Incubation for 30 min of liver microsomes from hibernating animals with dolichyl pyrophosphate N,N'-diacetyl-[14C]chitobiose and GDP-[14C]mannose led to the synthesis of lipid-[14C]trisaccharide. When liver microsomes were incubated with lipid-[14C]trisaccharide and unlabelled GDP-mannose, lipid-tetra- to heptasaccharides were discovered in the chloroform-methanol (2:1) extract. Since, under the experimental conditions, negligible synthesis of dolichyl phosphate mannose was observed, it was assumed that GDP-mannose was a donor of mannose in the conversion of lipid-trisaccharide into lipid-oligosaccharides containing 2-5 mannose residues.
B N
BN
Panayotov
V I
VI
Zhivkov
D000818:Animals; D002250:Carbon Radioisotopes; D006155:Guanosine Diphosphate Mannose / Q000378:metabolism; D006605:Hibernation; D006868:Hydrolysis; D008364:Mannosyltransferases / Q000378:metabolism; D008862:Microsomes, Liver / Q000378:metabolism*; D011104:Polyisoprenyl Phosphate Oligosaccharides / Q000096:biosynthesis* / Q000378:metabolism*; D011105:Polyisoprenyl Phosphate Sugars / Q000096:biosynthesis* / Q000378:metabolism*; D012589:Sciuridae / Q000378:metabolism*
D002250:Carbon Radioisotopes; D011104:Polyisoprenyl Phosphate Oligosaccharides; D011105:Polyisoprenyl Phosphate Sugars; C024962:dolichyl diphosphate oligosaccharides; D006155:Guanosine Diphosphate Mannose; C016418:dolichyl-diphosphate-di-N-acetylchitobiose; D008364:Mannosyltransferases