Structural analyses of mannose pentasaccharide of high mannose type oligosaccharides by 1D and 2D NMR spectroscopy

Abstract

NMR spectroscopy is a very important and useful method for the structural analysis of oligosaccharides, despite its low sensitivity. We first applied conventional measuring methods, 2D DQF COSY, (1)H-(13)C HSQC, and (1)H-(13)C HMBC, and also the Double Pulsed Field Gradient Spin Echo (DPFGSE)-TOCSY and DPFGSE-NOESY/ROESY techniques to analyze a branched mannose pentasaccharide as a model of high mannose type N-glycans in natural abundance. The NMR spectra of the model compound are very complex and difficult to analyze owing to overlapping signals. The superior selective irradiation capability of the DPFGSE technique is useful for fine structural and conformational analyses of such complex oligosaccharides. We here introduce a novel technique called DPFGSE-Double-Selective Population Transfer (SPT)-Difference and DPFGSE-NOE/ROE-SPT-Difference spectroscopy. The DPFGSE-Double-SPT-Difference method involves irradiation of two peaks from one proton and the subtraction of higher and lower peaks from each spectrum. The DPFGSE-NOE/ROE-SPT-Difference method involves the transfer of the magnetization polarized by NOE/ROE from the nuclei to the spin-coupled nuclei through scalar spin-spin interaction using the SPT method. Even if the signals in the NMR spectra overlap, each signal can be accurately assigned. In particular, DPFGSE-NOE/ROE-SPT-Difference is very useful for identifying sugar connectivity.

Conformation and Dynamics at a Flexible Glycosidic Linkage Revealed by NMR Spectroscopy and Molecular Dynamics Simulations: Analysis of β-l-Fucp-(1→6)-α-d-Glcp-OMe in Water Solution

“…[13][14][15][16][17][18] The conformational and dynamical properties of other (1→6)-linked disaccharides 17,[19][20][21] and larger oligosaccharides having this linkage 15,22 have been investigated.…”

Interactions of Glycopolymers with Assemblies of Peptide Amphiphiles via Dynamic Covalent Bonding

“…But in the present case, the low abundance of boron in PA makes this technique not practical. NOESY − is known to be powerful to characterize the neighboring atoms in close proximity. Thus, we tried to understand the possible binding mode between Man and BOB in the mixed PAA system by using NOESY.…”

Recent Advances in NMR Studies of Carbohydrates

“…In 2013, Kato and coworkers [1] presented an excellent review about new NMR tools for characterizing the dynamic conformation and interactions of oligosaccharides. A comprehensive overview of the advances in glycosaminoglycanomics such as chondroitin sulfate, dermatan sulfate, heparin, heparan sulfate, and hyaluronan by 15 N NMR spectroscopy has been written by Pomin [2]. Cyclic reports about NMR study of carbohydrates were published by Mlynarski et al [3][4][5].…”

“…Double-pulsed field gradient spin-echo (DPFGSE)-TOCSY and DPFGSE-NOESY/ROESY (rotating-frame Overhauser effect spectroscopy) were used to analyze branched mannose pentasaccharides [15]. Due to heavy overlapping, the superior signal-selective irradiation capability of the DPFGSE technique was applied.…”

“…The determination of the functional binding target of expansion in Arabidopsis thaliana cell walls (CW) by ssNMR combined with sensitivity-enhancing dynamic nuclear polarization (DNP) was described by Wang et al [24]. DNP modification allowed the selective detection of 13 C spin diffusion from trace concentrations of 13 C, 15 N-labeled expansion in the CW to nearby polysaccharides. Dick-P erez et al [25] studied cell-wall polysaccharides of uniformly labeled 13 C A. thaliana.…”