Schematic representation of the structure of native LTA from LGG wild-type determined by NMR spectroscopy analysis.1H-NMR spectra were analysed and integrated with Topspin 2.0 software. Based on the integrations of the corresponding signals in the spectra, the chain length (n) of the polyglycerolphosphate backbone was estimated between 30 and 78 depending on a biological variability (4 samples were tested). The second carbon of every glycerol was substituted with X, being either a hydroxyl group or D-alanine. The two acyl chains of LTA each have one double bound (of which the exact position was not determined) and have a total length of approximately n=14 (based on and confirmed by integration data from this study). For the biological LTA sample of LGG wild-type (see also Figure1), N = 30, while X = 71.8% D-Ala. For mLTA1, X = 15.6% D-Ala, while X = 0% for mLTA2. For mLTA2, 55% of the acyl chains of LTA were found to be removed.