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DOE OSTI · 3015075

Molecular Insights Into the Ionic Assembly of Poly-Galacturonic Acid Oligomers - Impact of Charge, Ionic Radius, and Polymer Functionalization

Bu, Lintao [National Laboratory of the Rockies, Golden, CO (United States)]·Crowley, Michael [National Laboratory of the Rockies, Golden, CO (United States)]·Sharma, Deepak [University of Georgia]·Urbanowicz, Breeanna [University of Georgia]·Bharadwaj, Vivek [National Laboratory of the Rockies, Golden, CO (United States)] (ORCID:0000000158519807)
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Abstract

Pectin, a major class of matrix polysaccharides present in plant cell walls (PCW), contains widespread anionic saccharides that cross-link in the presence of cations. It modulates important functions such as cell-cell adhesion and determines the PCW's biomechanical properties. It is known that mono-, di-, and tri-valent cations facilitate cross-linking; however, significant knowledge gaps remain in understanding the structure and mechanism of pectin cross-linking. In this study, replica-exchange molecular dynamics (REMD) simulations were employed to elucidate the role of ionic charge, ionic radii, and functional groups on the cross-linking of homogalacturonan (HG), the most abundant pectin molecule. Our enhanced sampling approach in fully solvated environments suggests more effective cross-linking with higher-valent and smaller ions, and that the "zipper" conformation is more favorable than the prevalent "egg-box" conformation. These findings advance our fundamental understanding of pectin matrix structure in PCWs and provide a solid foundation to probe structure-property relationships in pectic polysaccharides.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY97 MATHEMATICS AND COMPUTINGcross-linkingHomogalacturonanionic assemblymolecular dynamicspectinreplica-exchange sampling

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Bu, Lintao [National Laboratory of the Rockies, Golden, CO (United States)], Crowley, Michael [National Laboratory of the Rockies, Golden, CO (United States)], Sharma, Deepak [University of Georgia], Urbanowicz, Breeanna [University of Georgia], Bharadwaj, Vivek [National Laboratory of the Rockies, Golden, CO (United States)] (ORCID:0000000158519807). 2025-12-30. Molecular Insights Into the Ionic Assembly of Poly-Galacturonic Acid Oligomers - Impact of Charge, Ionic Radius, and Polymer Functionalization. https://doi.org/10.1002/jcc.70298

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