[Sensitivity of mannosyl transferases from Salmonella serotype E1 and B to modification of the donor heterocyclic base].

A series of synthetic nucleoside diphosphate mannoses with different heterocyclic bases were tested as GDP-Man analogues in enzymatic mannosylation during assembly of O-antigen repeating units of Salmonella anatum and Salmonella typhimurium. The substrate efficiency was found to depend strongly on oxygen atom presence at C6 of the purine residue, the H2N-C2-N1-H grouping of the heterocyclic nucleus being less important. UDP-Man proved to be an efficient substrate for the mannosylation reactions.