Loss of D-alanine during sublethal heating of Staphylococcus aureus S6 and magnesium binding during repair.
Staphylococcus aureus S6 sublethally heated at 52 degrees C for 15 min to 0-1 M-potassium phosphate buffer pH 7-2, lost neither the ribitol teichoic acid of the wall nor the glycerol teichoic acid of the membrane. Hurst et al. (1974) showed that this heating caused 40% loss of the cellular Mg, and we now report the loss of 65% of the ester-bound D-alanine of teichoic acid. Repair from sublethal heat injury, measured by the return of salt tolerance, occurs in a simple no-growth medium provided that the cell concentration is less than 5 x 10(8)/ml. During repair, D-alanine is rapidly synthesized. Fully-repaired cells contain four times more D-alanine than do freshly-injured cells. Magnesium is present in the medium at only 3 x 10(-6) M, yet the cellular Mg concentration returns to normal within 1 h of incubation, even in the presence of EDTA. The results suggest that repair occurs in two stages. Soon after injury, in the absence of the competitive effect of D-alanine, Mg is strongly bound to teichoic acid. In repaired or uninjured cells Mg is less strongly bound. The implications of these findings are discussed in relation to the cation-binding function of teichoic acid.
D000409:Alanine / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D006358:Hot Temperature; D050356:Lipid Metabolism; D008274:Magnesium / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000378:metabolism*; D013682:Teichoic Acids / Q000378:metabolism
D013682:Teichoic Acids; D008274:Magnesium; D000409:Alanine