METHYLESTERS OF L-ARGININE AND N-NITRO-L-ARGININE INDUCE NITRIC-OXIDESYNTHASE IN STAPHYLOCOCCUS-AUREUS

The presence of L-arginine methylester (AME), L-arginine ethylester (A EE), or N-nitro-L-arsnine methylester (NAME) in the growth media of St aphylococcus aureus increased the nitric oxide synthase (NOS) activity approximately 5- to 14-fold. The increase of NOS activity was confirm ed by two assay methods, namely assaying the formation of L-[H-3] citr ulline from L-[H-3] arginine and NO formation. The increase of NOS act ivity was most likely due to increased de novo synthesis, demonstrated by Western immunoblot analysis. The addition of methanol to the cultu re medium also increased the NOS activity as much as that found with t he above three compounds. Evidence is presented to show that AME, AEE, or NAME gave rise to the formation of methanol in vivo by the action of intracellular esterase(s) and that methanol is subsequently involve d in the induction of NOS in this bacterial system. (C) 1998 Academic Press.