Charting the solid‐state NMR signals of polysaccharides: A database‐driven roadmap

Abstract

Solid‐state nuclear magnetic resonance (ssNMR) measurements of intact cell walls and cellular samples often generate spectra that are difficult to interpret due to the presence of many coexisting glycans and the structural polymorphism observed in native conditions. To overcome this analytical challenge, we present a statistical approach for analyzing carbohydrate signals using high‐resolution ssNMR data indexed in a carbohydrate database. We generate simulated spectra to demonstrate the chemical shift dispersion and compare this with experimental data to facilitate the identification of important fungal and plant polysaccharides, such as chitin and glucans in fungi and cellulose, hemicellulose, and pectic polymers in plants. We also demonstrate that chemically distinct carbohydrates from different organisms may produce almost identical signals, highlighting the need for high‐resolution spectra and validation of resonance assignments. Our study provides a means to differentiate the characteristic signals of major carbohydrates and allows us to summarize currently undetected polysaccharides in plants and fungi, which may inspire future investigations.

Molecular Architecture of Chitin and Chitosan-Dominated Cell Walls in Zygomycetous Fungal Pathogens by Solid-State NMR

“…Although GlcA was reported to be abundant in some Mucorales 18 , we were unable to identify its signals in any of our spectra. To further validate this, we extracted chemical shift datasets available at the Complex Carbohydrate Magnetic Resonance Database 45 for both GlcA and galacturonic acid (GalA), which has a similar structure, to construct simulated NMR spectra 46 . Overlaying these simulated spectra with experimentally measured spectra confirmed the absence of GlcA residues in our sample ( Supplementary Fig.…”

New Vision of Cell Walls in Aspergillus fumigatus from Solid-State NMR Spectroscopy

“…The same is not true, however, for rigid and fibrillar components, such as chitin in fungi and cellulose in plants [29,41]. A more in-depth exploration of the complexity of the structure and chemical shifts observed in cellular carbohydrates can be found in a recent review [42], and the NMR fingerprint of fungal carbohydrate can be accessed here [43]. Using chitin as an example, this chemically simple polymer, composed of β-1,4linked N-acetylglucosamine (GlcNAc) units, was traditionally perceived as being uniform.…”

“…The same is not true, however, for rigid and fibrillar components, such as chitin in fungi and cellulose in plants [ 29 , 41 ]. A more in-depth exploration of the complexity of the structure and chemical shifts observed in cellular carbohydrates can be found in a recent review [ 42 ], and the NMR fingerprint of fungal carbohydrate can be accessed here [ 43 ].…”

Chronological Molecular Fingerprint of Wetland Soil by Sensitivity-Enhanced Solid-State NMR

“…320 scans were collected for the soil sample in 16 h, and 160 scans were collected for each of the two plant samples, with experimental time of 13 h and 23 h for the plants on the edge and inland, respectively. To rapidly identify the key carbohydrate components in soil, a probability map was built by extracting 412 datasets of plant carbohydrates from the Complex Carbohydrate Magnetic Resonance Database 36 following a recently reported protocol 67 . All 13 C and 1 H chemical shifts of identified polymers are documented in Supplementary Table 4.…”