Sucralose Interaction with Protein Structures

TL;DR

This study compares sucralose and sucrose, revealing that sucralose destabilizes proteins at higher concentrations and stress conditions due to weak hydrophobic interactions, unlike sucrose which stabilizes proteins.

Contribution

It provides a detailed molecular analysis of how sucralose interacts differently with proteins compared to sucrose, explaining its reduced bio-preservative efficacy.

Findings

Sucralose does not disturb native protein structures at moderate concentrations.

Higher sucralose concentrations or thermal stress reduce protein stability.

Sucralose's increased hydrophobicity weakens its interaction with proteins.

Abstract

Sucralose is a commonly employed artificial sweetener that appears to destabilize protein native structures. This is in direct contrast to the bio-preservative nature of its natural counterpart, sucrose, which enhances the stability of biomolecules against environmental stress. We have further explored the molecular interactions of sucralose as compared to sucrose to illuminate the origin of the differences in their bio-preservative efficacy. We show that the mode of interactions of sucralose and sucrose in bulk solution differ subtly using hydration dynamics measurement and computational simulation. Sucralose does not appear to disturb the native state of proteins for moderate concentrations (<0.2 M) at room temperature. However, as the concentration increases, or in the thermally stressed state, sucralose appears to differ in its interactions with protein leading to the reduction of native state stability. This difference in interaction appears weak. We explored the difference in the preferential exclusion model using time-resolved spectroscopic techniques and observed that both molecules appear to be effective reducers of bulk hydration dynamics. However, the chlorination of sucralose appears to slightly enhance the hydrophobicity of the molecule, which reduces the preferential exclusion of sucralose from the protein-water interface. The weak interaction of sucralose with hydrophobic pockets on the protein surface differs from the behavior of sucrose. We experimentally followed up upon the extent of this weak interaction using isothermal titration calorimetry (ITC) measurements. We propose this as a possible origin for the difference in their bio-preservative properties.