Conformational Properties of Single-Chain Polyuronates: A Comparative Molecular Simulation Study of Polyglucuronates,...

Area of Science:

• Polymer Science
• Biochemistry
• Computational Chemistry

Background:

• Polyuronates are natural polyelectrolytes with diverse applications.
• Linear polysaccharides like alginates exhibit distinct conformational properties despite similar chemical structures.
• Understanding these properties is crucial for their effective utilization.

Purpose of the Study:

• To perform a detailed conformational analysis of individual polyuronate chains, including heterogeneous alginates.
• To investigate the relationship between molecular structure and chain rigidity.
• To explore the influence of alginate block composition on its global conformation.

Main Methods:

• Utilized atomistic molecular dynamics simulations.
• Employed Monte Carlo simulations with a coarse-grained model for longer chains.
• Analyzed local chain stiffness using persistence length and characteristic ratio.

Main Results:

• Established a correlation between chain stiffness descriptors and the dominant 'syn-exo' conformation.
• Found that alginate block composition has a limited effect on global conformation for longer chains.
• Identified monomer content (mannuronate and guluronate) as the primary factor influencing alginate conformation.
• Observed significant increases in persistence length at extremely low ionic strength, dependent on alginate composition.

Conclusions:

• Alginate conformational properties are primarily determined by the M/G monomer content, not block sequence.
• Extremely low ionic strength conditions offer a potential method for estimating alginate composition through conformational analysis.