Figure 1.
The structure of the adjuvant developed in the present study, a synthetic Toll‐like receptor (TLR)‐2 ligand containing the RGDS motif. (a) The structure of macrophage‐activating lipopeptide (MALP)‐2. The N‐terminal cysteine of a peptide derived from a mycobacterium is modified with 2 palmitates [Pam2Cys, P2C, S‐(2,3‐bispalmitoyloxypropyl)cysteine]. RGDS was conjugated to P2C to form P2C‐RGDS because of its hydrophilicity and its additional function as an integrin‐binding motif for cell adhesion. (b) The structure, molecular weight, isoelectric point (pI), and hydrophobicity of synthetic (P2C‐RGDS, P2C‐SKKKK) and natural (MALP‐2, FSL‐1) lipopeptides used in this study. The pI and hydrophobicity of the peptide were calculated using ProtParam tools (http://br.expasy.org/tools/protparam.html). The pI and hydrophobicity of P2C‐RGDS were almost equivalent to those of MALP‐2. The molecular weight of P2C‐RGDS was about half that of MALP‐2. N, natural TLR2 ligand; S, synthetic TLR2 ligand. The asterisks (*) indicate acidic peptides. The gray boxes indicate hydrophobic amino acids.