DISTRIBUTION OF LIPID-A SPECIES BETWEEN LONG AND SHORT-CHAIN LIPOPOLYSACCHARIDES ISOLATED FROM SALMONELLA, YERSINIA, AND ESCHERICHIA AS SEEN BY CF-252 PLASMA DESORPTION MASS-SPECTROMETRY

Smooth type endotoxins of Salmonella, Yersinia, and Escherichia were f ractionated into long and short chain lipopolysaccharides by silica ge l chromatography. Lipid A was prepared from the fractions and analyzed by plasma desorption mass spectrometry. Both Yersinia and Salmonella endotoxins had a large proportion of aminoarabinose-containing lipopol ysaccharide molecular species that were found to be concentrated in th e long chain fraction, In the Escherichia endotoxin, hypoacylated lipo polysaccharides (lacking the tetradecanoate and one of the four hydrox ytetradecanoates) were found mostly in the short chain fraction, Possi ble implications of these results for the lipopolysaccharide biosynthe tic pathway and for studies on the influence of sugar chain length on the biological effects of endotoxins are discussed,