FIG. 1.

Variation in lipid A structure determined by MALDI-TOF MS from P. gingivalis cells grown in continuous culture at 37°C, 39°C, and 41°C. Bacteria grown at 37°C produce mainly tetra-acylated, nonphosphorylated lipid A and tetra-acylated, monophosphorylated lipid A bearing a 1-phosphate. However, when the growth temperature is maintained at 41°C, a penta-acylated, monophosphorylated lipid A predominates concomitant with reduction in both the nonphosphorylated and monophosphorylated, tetra-acylated lipid A structures.