Conformational stability of homogalacturonan pectin in water and dry environments: A molecular dynamics study

Abstract: Pectin is a crucial polysaccharide in plant primary cell walls. Despite its wide applications, the conformational stability of homogalacturonan pectin under different environmental conditions remains an area of ongoing investigation. To address this issue, molecular dynamics simulation is used to analyze the conformations of pectin in dry and aqueous environments. The results reveal that pectin adopts a 2-fold helical structure in dry conditions. In the presence of explicit water molecules, a 3-fold helical structure occurs. This conformational shift is driven by hydrogen bond formation. The number of hydrogen bonds increases from 0.8 to 5.1 per repeat unit of pectin in the hydrated state, with water molecules acting as key donors for hydrogen bonds. These findings provide insight into the conformations of pectin and contribute to a deeper understanding of its structural stability in various environments.