MDP

Muramyl dipeptide (MDP) is the minimal bioactive peptidoglycan motif common to all bacteria, the essential structure required for adjuvant activity in vaccines.

MDP has been shown to be recognized by NOD2, but not TLR2, nor TLR2/1 or TLR2/6 associations [1, 2]. This recognition is highly stereospecific of the L-D isomer, excluding any reaction to the D-D or L-L analogs [2].

The potent adjuvant activity of MDP may be linked to an activation of the CIAS1/NALP3/Cryopyrin inflammasome [3].

References:

1. Girardin SE. et al., 2003. Nod2 is a general sensor of peptidoglycan through muramyl dipeptide (MDP) detection. J Biol Chem. 278(11):8869-72.
2. Inohara N. et al., 2003. Host recognition of bacterial muramyl dipeptide mediated through NOD2. Implications for Crohn's disease.J Biol Chem. 278(8):5509-12.
3. Martinon F. et al., 2004. Identification of bacterial muramyl dipeptide as activator of the NALP3/cryopyrin inflammasome. Curr Biol. 14(21):1929-34.