Sph3h and PelAh
are endo-N-acetylgalactosaminidases with a minimum substrate size of seven residues. Degradation time course of pure oligosaccharides monitored over 30 min by MALDI-TOF MS. Sph3h degradation kinetic of: A, α-1,4-GalNAc 6-mers and B, α-1,4-GalNAc 7-mers. PelAh degradation kinetic of: C, α-1,4-GalNAc 6-mers and D, α-1,4-GalNAc 7-mers. Relative proportion of each ions was calculated and reported here under the color purple for 7-mer; green for 6-mer, blue for 5-mer, red for 4-mer, and yellow for 3-mer.