Specific binding sites of muroctasin on murine macrophages.

The specific binding sites for N2-[N-acetylmuramoyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-lysine (MDP-Lys(L18), muroctasin), a synthetic muramyl dipeptide analog, on murine macrophages were investigated using [3H]-MDP-Lys(L18). The specific binding sites were found to be located on macrophage membrane and not to cross-react with MDP. It was also found that MDP-Lys(L18) was not metabolized by macrophages.