BPPSCTS OF PHNICILLIN OM BACTERIAL CSLL WALL SYNIREGIS IM 2. COLT AMD

IN 3, AURSUS. 3. Mathengson*® and J. L. Strouinger. Dept. of Pharmacology,

Washington Univ. School of Medicine, “*. Louis. f 5
Several Lines of avidence indicating that penicillin interfere

specifically with the synthesis of the cei: wail of 3. mureug are \

substantiated by the folloving experiments: Incorporation of c)¥-,

“An

*

lysine into cell wall was inhibited 91% wy penicillin under conditions A
where incorporation into cell protein was diminished by only 2%. |
Similarly, incorporation of 732-inorganic phosphate into the cell .

wall of 3. aureus was inhibited 68% under conditions where no .
inhibition of incorporation waa observed into the cold TCA

precipitate of the cell contents. In 2, coli, where wuc ceil wall 4
atrucitre is more complex, incorporation of H-diaminopimelic acid
into celi well ves inhibited 72% vhere c}4-giucose incorporation
into cell wall wae inhibited only 14f (double labeling experiuent).
An 8. coli mutant requiring poth DAP and lysine, kindly given by

J. laderberg, was used in these experiments. These observations
provide direct evidence that penicillin inhibits the synthesis of
the “basal structure of the ceil wall in both 5. gureus and 3 coli.
In & coli, the teain’ fraction of the complex cell wall is a ‘super-
etructure” containing protein and lipid, the synthesise of which from
o}4. gi ncose is not inhibited by penicillin (cf. Trucco and Pardee,

3. Biol. Chem. 230:435, 1958, whose conflicting cone Lust ons are
resolved by these experiments). (Supported by NIAID Grant)