Biosynthesis of agglomerin A: stereospecific incorporation of pro-R- and pro-S-hydrogens at sn-C-3 of glycerol into the branched C3 moiety

The biosynthetic origin of the C3 branched unit of agglomerin A has been investigated. Feeding of sn-(3R)- and sn-(3S)-[3-2H]glycerols to Enterobacter agglomerans PB-6042 followed by 2H NMR analysis of the resulting agglomerin A revealed that pro-R and pro-S hydrogens at sn-C-3 of glycerol were incorporated stereospecifically into 5E and 5Z hydrogens of agglomerin A, respectively. These results imply that the immediate precursor of the C3 branched unit is not pyruvate, but 1,3-bisphosphoglyceric acid or its biological equivalent.