Figure 4

Time-resolved NMR showing epimerization of 13C-labeled mannuronan with AcAlgE1. The position of the triads in the spectra is indicated, and the M or G moiety generating the signal is underlined. The spectra were recorded, processed and analyzed using TopSpin 3.6pl7 software (Bruker BioSpin) and finalized in Adobe Illustrator 2020 (Adobe Systems, USA).