≈ 3), corresponding to an estimated electrostatic potential of approximately -216 ± 8 mV. This behaviour is consistent with the localisation of the probe in a strongly anionic microenvironment associated with the RNA-containing interior rather than the capsid surface. Comparative analysis with anionic micellar systems, liposomes, DNA solutions, and protein-based media showed that similar spectral shifts occur only in highly anionic environments. Molecular dynamics simulations support these findings and indicate preferential localisation of the probe inside the capsid in proximity to RNA. These results demonstrate that the MS2 interior is characterized by a highly negative electrostatic potential governed by genomic RNA and illustrate the applicability of molecular probes for studying nanoscale electrostatic environments in viral systems.
Vodolazkaya et al. (Tue,) studied this question.