DNP-supported solid-state NMR studies of 13C,15N,29Si-enriched biosilica of Cyclotella cryptica and Thalassiosira pseudonana

Abstract Solid-state NMR spectroscopy represents a powerful method for the investigation of diatom biosilica but detailed studies regarding its chemical composition and structural organization can be prohibited by insufficient spectroscopic sensitivity. Here, we used two-dimensional (2D) Dynamic Nuclear Polarization (DNP)-supported solid-state experiments to obtain information about molecular supramolecular proteins carbohydrates in 13 C, 15 N, 29 Si-labeled C. cryptica. As reference, conducted DNP on isotope-labeled T. pseudonana . DNP-enhancement factors different signals, thus, organic compounds, provide architecture biosilica. In addition, DNP-supported heteronuclear nitrogen-carbon correlation allowed us prove presence elements long chain polyamines (LCPAs) revealed occurrence amine-nitrogen moieties exhibiting with carbonyl carbons that may indicate cross-linking LCPAs as previously seen extracted from other diatoms.