Figure 4
Calculated biosynthetic pathways of human milk oligosaccharides. (A) Simulated network of the 11 enzymes of Table 2, limiting to 11 iterations, with each HMO limited to a maximum of 4 GlcNAc residues. (B) As A, with 195 experimentally characterised HMOs highlighted and coloured, with theoretical structures shown in grey. (C) A minimal reaction network leading to the population of 206 HMOs from the library of observed HMOs (Supplementary Table S1). (D) As C, with only the experimentally observed HMOs highlighted. The position of the starting substrate, lactose, is indicated by a black arrow. Nodes are coloured according to the base core configuration given in Fig. 1: magenta (1/1), blue (2/1), green (1/2), orange (2/2), red (0/1), cyan (0/2), grey (other, unclassified). The locations of DSLNT and inverse-LNnD, within networks B and D, are indicated by red and orange arrows, respectively. Networks were drawn in Tulip 72 using a stress-minimization layout algorithm.
