| 1. |
- Battistel, Marcos D., et al.
(author)
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Direct Evidence for Hydrogen Bonding in Glycans : A Combined NMR and Molecular Dynamics Study
- 2013
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In: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 117:17, s. 4860-4869
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Journal article (peer-reviewed)abstract
- We introduce the abundant hydroxyl groups of glycans as NMR handle's and structural probes to expand the repertoire of tools for structure function studies on glycans in solution. To this end, we present the facile detection and assignment of hydroxyl groups in a Wide range of sample concentrations (0.5-1700 mM) and temperatures, ranging from -5 to 25 degrees C.,We then exploit this information to directly detect hydrogen bonds, well-known for their importance in molecular structural determination through NMR. Via HSQC-TOCSY, we were able to determine the directionality; of these hydrogen bonds in sucrose Furthermore, by means Of molecular dynamics simulations in conjunction with NMR, we establish that one Out of the three detected hydrogen bonds arises from intermolecular interactions. This finding may shed light on glycan glycan interactions and glycan recognition by proteins.
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| 2. |
- Brinson, Robert G., et al.
(author)
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Enabling adoption of 2D-NMR for the higher order structure assessment of monoclonal antibody therapeutics
- 2019
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In: mAbs. - : Informa UK Limited. - 1942-0862 .- 1942-0870. ; 11:1, s. 94-105
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Journal article (peer-reviewed)abstract
- The increased interest in using monoclonal antibodies (mAbs) as a platform for biopharmaceuticals has led to the need for new analytical techniques that can precisely assess physicochemical properties of these large and very complex drugs for the purpose of correctly identifying quality attributes (QA). One QA, higher order structure (HOS), is unique to biopharmaceuticals and essential for establishing consistency in biopharmaceutical manufacturing, detecting process-related variations from manufacturing changes and establishing comparability between biologic products. To address this measurement challenge, two-dimensional nuclear magnetic resonance spectroscopy (2D-NMR) methods were introduced that allow for the precise atomic-level comparison of the HOS between two proteins, including mAbs. Here, an inter-laboratory comparison involving 26 industrial, government and academic laboratories worldwide was performed as a benchmark using the NISTmAb, from the National Institute of Standards and Technology (NIST), to facilitate the translation of the 2D-NMR method into routine use for biopharmaceutical product development. Two-dimensional H-1,N-15 and H-1,C-13 NMR spectra were acquired with harmonized experimental protocols on the unlabeled Fab domain and a uniformly enriched-N-15, 20%-C-13-enriched system suitability sample derived from the NISTmAb. Chemometric analyses from over 400 spectral maps acquired on 39 different NMR spectrometers ranging from 500 MHz to 900 MHz demonstrate spectral fingerprints that are fit-for-purpose for the assessment of HOS. The 2D-NMR method is shown to provide the measurement reliability needed to move the technique from an emerging technology to a harmonized, routine measurement that can be generally applied with great confidence to high precision assessments of the HOS of mAb-based biotherapeutics.
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| 3. |
- Kwon, Jeahoo, et al.
(author)
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Glycan Stability and Flexibility : Thermodynamic and Kinetic Characterization of Nonconventional Hydrogen Bonding in Lewis Antigens
- 2023
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In: Journal of the American Chemical Society. - 0002-7863 .- 1520-5126. ; 145:18, s. 10022-10034
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Journal article (peer-reviewed)abstract
- We provide evidence for CH-based nonconventional hydrogen bonds (H-bonds) for 10 Lewis antigens and two of their rhamnose analogues. We also characterize the thermodynamics and kinetics of the H-bonds in these molecules and present a plausible explanation for the presence of nonconventional H-bonds in Lewis antigens. Using an alternative method to simultaneously fit a series of temperature-dependent fast exchange nuclear magnetic resonance (NMR) spectra, we determined that the H-bonded conformation is favored by ∼1 kcal/mol over the non-H-bonded conformation. Additionally, a comparison of temperature-dependent 13C linewidths in various Lewis antigens and the two rhamnose analogues reveals H-bonds between the carbonyl oxygen of the N-acetyl group of N-acetylglucosamine and the OH2 group of galactose/fucose. The data presented herein provide insight into the contribution of nonconventional H-bonding to molecular structure and could therefore be used for the rational design of therapeutics.
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| 4. |
- Norris, Scott E., et al.
(author)
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Transient hydrogen bonding in uniformly 13C, 15N labeled carbohydrates in water
- 2012
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In: Biopolymers. - : Wiley Periodicals, Inc.. - 0006-3525 .- 1097-0282. ; 97:3, s. 145-154
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Journal article (peer-reviewed)abstract
- We report NMR studies of transient hydrogen bonding in a polysaccharide (PS) dissolved in water without cosolvent at ambient temperature. The PS portion of the Escherichia coli O142 lipopolysaccharide is comprised of repeating pentasaccharide units of GalNAc (N-acetyl galactosamine), GlcNAc (N-acetyl glucosamine), and rhamnose in a 3:1:1 ratio, respectively. A 105-ns molecular dynamics (MD) simulation on one pentasaccharide repeat unit predicts transient inter-residue hydrogen bonds from the GalNAc NH groups in the PS. To investigate these predictions experimentally, the PS was uniformly 13C,15N enriched and the NH, carbonyl, C2, C4, and methyl resonances of the GalNAc and GlcNAc residues assigned using through-bond triple-resonance NMR experiments. Temperature dependence of amide NH chemical shifts and one-bond NH J couplings support that NH groups on two of the GalNAc residues are donors in transient hydrogen bonds. The remaining GalNAc and GlcNAc NHs do not appear to be donors from either temperature-dependent chemical shifts or one-bond NH J couplings. These results substantiate the presence of weak or partial hydrogen bonds in carbohydrates, and that MD simulations of repeating units in PSs provide insight into overall PS structure and dynamics.
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