Enzymatic synthesis of 2-O-alpha-D-mannopyranosyl-methyl-alpha-D-mannopyranoside by a cell-free particulate system of Mycobacterium smegmatis.
A cell-free particulate enzyme preparation of Mycobacterium smegmatis ATCC 607 catalyzed the transfer of labeled mannose from GDP[14C] mannose to methyl-alpha-D-mannopyranoside (an exogenously added acceptor) to form a product that was characterized to be 2-O-alpha-D[14C] mannopyranosyl-methyl-alpha-D-mannopyranoside. This transmannosylase activity was specific for both the sugar nucleotide donor and methyl monosaccharide acceptor. The reaction was stimulated by the addition of various metal ions and had a pH optimum of 6.0. The apparent Km of this transmannosylase reaction for methyl-alpha-D-mannopyranoside was 35 mM. The possible relationship between this "artificial" mannosyl-transfer system and the "natural" system which leads to the formation of the oligomannosides and glycoproteins is discussed.
D002474:Cell-Free System; D004187:Disaccharides / Q000096:biosynthesis*; D004492:Edetic Acid / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008364:Mannosyltransferases / Q000378:metabolism; D008759:Methylglycosides / Q000096:biosynthesis*; D008766:Methylmannosides / Q000096:biosynthesis*; D009161:Mycobacterium / Q000378:metabolism*; D010618:Phenanthrolines / Q000494:pharmacology; D013696:Temperature
D004187:Disaccharides; D008759:Methylglycosides; D008766:Methylmannosides; D010618:Phenanthrolines; D004492:Edetic Acid; D008364:Mannosyltransferases; D008274:Magnesium