Enzymic synthesis of a diamino sugar nucleotide by extracts of type XIV Diplococcus pneumoniae.

We previously reported that incubation of the appropriat’e sugar nucleotides with extracts obtained from Type XIV Diplococcus pneumoniae resulted in the formabion of glycolipids and serologically active polysaccharides (1, 2). During the course of these studies, we observed the formation of an unusual sugar nucleotide when the extracts were incubated with UDP-N-acetylglucosamine. As shown below, the new nucleotide is UDP-2-acetamido-4 amino-2,4,6-trideoxyhexose. The extra&s also transferred t)he cliamino sugar t,o endogenous lipid acceptors. While diamino sugars are found in a few antibiotics (3), the only report of the occurrence of a 2,4-diamino-2,4,6-trideoxyhexose is that by Sharon and Jeanloz (4) ; the unusual amino sugar was a component of a polysaccharide produced by a strain of Bacillus subtilis. The amino sugar, called bacillosamine, was obtained as the 4-N-acetyl derivative after acid hydrolysis of the polysaccharide. Recently, Zehavi and Sharon (5) have identified bacillosamine as 2,4-diamino-2,4,6-trideoxy-L-altrose. Whether bacillosamine is identical to, or a diastereoisomer of the amino sugar reported below has not yet been established. Two enzyme fract’ions were required for the synthesis of the UDP derivative of the diamino sugar. They catalyzed the following reactions: